Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：Domestic journal  

DOI： https://doi.org/10.2208/kaigan.78.2_I_625

Authorship：Corresponding author   International / domestic magazine：Domestic journal  

DOI： https://doi.org/10.3811/jjmf.2022.020

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：Domestic journal  

DOI： https://doi.org/10.3811/jjmf.2022.018

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：Domestic journal  

DOI： https://doi.org/10.2208/jscejoe.78.2_I_367

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：International journal  

Nature-based solutions (NbS), such as the implementation of environmental
conservation and restoration as public works projects, require accurate and cost-effective assessments of the values related to the projects. The values should
represent collective ecosystem services, individual services such as food provision and water purification, and other intangible services. To comprehensively assess such services, we proposed a novel method, which we call the comparative evaluation method. Our method is able to assess the value of each service category of an NbS project from a single questionnaire survey. Survey participants are asked to compare values of multiple services having anchoring prices. Our method determines the permissible economic value of
environmental public works (PEP) in response to the
quantity of service. The questionnaire results used for analysis are limited to those from respondents who made their PEP evaluation on the basis of their consideration of the appropriate expenditure of taxes. In addition, the method controls for the effect of
the satisfaction that a person experiences from doing good deeds to reduce an overestimation of the values of services. Moreover, PEPs are not influenced by the
respondent’s annual income, age, sex, or educational background , and are based on personal values. Applying this new method, we surveyed residents of the watersheds of Tokyo Bay and Osaka Bay and evaluated nine ecosystem services. Overall, our new method is shown to be an effective method for evaluating the ecosystem services of NbS projects from the viewpoint of public works.

DOI： https://doi.org/10.1016/j.ocecoaman.2021.105848

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

Green port structures (i.e. green infrastructure in ports and harbors) featuring habitats for marine organisms have been promoted in Japan as part of a comprehensive policy to reduce the environmental impact of ports and carry out habitat conservation, restoration, and creation. In this study, we evaluated the ecosystem services provided by green port structures in two highly urbanized bays (Tokyo Bay and Osaka Bay) in Japan. Our results show that the provision of some ecosystem services can be limited by circumstances particular to ports and other areas with restricted access. In the case of green port structures that have strong usage restrictions, for example, cultural services can only be provided if relevant authorities are prepared to conduct public events while ensuring participant safety. On the other hand, green port structures with weak usage restrictions are often equipped with incidental facilities such as parking lots and restrooms; these facilities can enhance the provision of cultural services (e.g. recreation and environmental education). Green port structures in highly urbanized bays often have usage restrictions, but their proximity to large populations means that they can potentially provide numerous ecosystem services. However, our study shows that appropriate management goals, such as protecting species and ensuring healthy habitats, are needed to maintain the value of these services in highly urbanized and eutrophic bays.

DOI： 10.1080/21664250.2021.1911194

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

DOI： https://doi.org/10.2208/jscejoe.77.2_I_271

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

DOI： 10.1299/transjsme.20-00247

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

Details of a velocity field around a prolate spheroid in a steady flow with different angles of attack were investigated by carrying out a hydraulic experiment using the PTV technique. It was found that characteristics of the vortex in the wake of the prolate spheroid were different depending on the angle of attack. It was clearly found that the velocity field changes significantly in the wake. That is to say that there were some areas with strong and weak turbulence and that also some areas with a certain periodic and unclear periodic velocity change with significant change. It was clear that these characteristics depend on the angle of attack of the spheroid. Further, it was confirmed that the distribution of the turbulence intensity was different between the horizontal and vertical components, and that the distribution area of the shear velocity was almost consistent with that of the horizontal component of the turbulence intensity.

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

DOI： https://doi.org/10.2208/kaigan.75.I_1

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

DOI： https://doi.org/10.2208/jscejoe.75.I_409

Authorship：Last author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

DOI： https://doi.org/10.2208/kaigan.74.I_991

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

Since local scouring occurring at the foot of a flow-sediment control structure impairs the stability of the structure itself, it is required to take some measures by predicting the scale of the scouring. In this study, the hydraulic experiment was carried out to investigate the effect of the vertical plate on the scouring charactersitics by observing the flow and sand migration phenomena in the vicinity of the vertical plate on the flat sand bed in detail. Based on the experimental result, the mechanism of local scouring was intellectualized and factors affect the characteristics of the local scouring were considered.

DOI： https://doi.org/10.2208/kaigan.74.I_829

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

In this study, the tidal flat health index (THI) was applied to four tidal flats in Osaka Bay to confirm the versatility of THI and understand the features in each tidal flat by comparing them with four tidal flats in Tokyo Bay. The reference values (the best score of each health index) in the services, such as food supply and water purification, related to the ecosystem states, in Osaka Bay were almost equal to those of Tokyo Bay. The reference values in the services, such as tourism and recreation, influenced by the regional population, were higher in Tokyo Bay than in Osaka Bay. However, the reference value of education was higher in Osaka Bay compared to Tokyo Bay, suggesting that environmental learning is active in Osaka. Principal component analysis of the nine services in the eight tidal flats in Osaka Bay and Tokyo Bay revealed that 74% of the THI scores could be explained by 2 components: "utilization of people" and "biodiversity".

DOI： https://doi.org/10.2208/kaigan.74.I_1417

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：International journal  

The microscopic structures of over and inside flow of a porous medium placed in oscillatory flow was measured by the Particle Tracking Velocimetry with the refractive index matching method in order to investigate interaction between them. The strong shear flow was observed over the surface of the porous medium and the thickness of shear flow varied with the phase of the oscillatory flow. It was found that the thickness of non-dimensional shear flow was almost constant and that it did not depend on the Reynolds number. It was found that the thickness of non-dimensional shear flow was almost constant and it independented with the Reynolds number. Besides, it was also found that the phase difference between flows over and inside the porous bed occurred. The characteristics of the spatial variance of velocity components were shown in detail with the time phase variance. Further, the flow properties around the particle constitutes porous body were measured and investigated in detail.

DOI： https://doi.org/10.2112/SI85-197.1

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

A new wave power generation system is proposed to be installed in a vertical slit type breakwater. The merits of the system are as follows: (i) no occupation of sea surface, (ii) low cost maintenance, and (iii) high energy efficiency by using accelerated flow from the slit of breakwater. In this study, a new, higher efficiency generator is proposed. An elastic rectangular plate connected to a wheel and axle via a wire is set in the water chamber. When the wave drag bends the plate, tension appears in a wire causes rotation of a wheel connected to a generator. To estimate the power of the proposed system at full scale, the wave energy flowing into the breakwater was simulated numerically. The results show that more than 60% of the wave energy is collected in the water chamber behind the slit with a small opening ratio. Although the output power of the bending plate is rather small, the power per unit of occupied sea area is somewhat superior to that of existing systems.

DOI： https://doi.org/10.11395/aem.3.0_98

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：Domestic journal  

Since the local scour, which occurs at the foot of the structure for controlling the drift sand and the flow, greatly affect the stability of the structure, the appropriate countermeasure should be taken based on the prediction of scale of the scour. In this study, the flow and sand migration phenomena formed in the vicinity of the vertical flat plate were observed in detail by using a high speed camera and the effect of the height of the vertical plate on the characteristics of the local scour at the foot of the plate was investigated in hydraulic experiment. On the basis of the observation the mechanisms of the occurrence of scour was inferred. Further the countermeasures of penetration of the vertical plate into sand bed and embankment at the foot of the vertical plate were proposed and the effectiveness of them were investigated.

DOI： 10.2208/jscejoe.74.I_814

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

本研究では，大阪市立大学工学部G棟屋上に雨量計を設置して降水量を計測し，大阪気象台および堺地方気象観測所における降水観測結果と比較することによって，空間的な降水量の偏差特性について検討した．また，高解像度降水ナウキャストの画像データを自動で取得するシステムを構築し，予測情報を収集して予測降水量の確からしさの検討に資するデータをアーカイブするシステムを濃く馳駆した．

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

In this study, a numerical model for calculation of fluid motion induced by an object penetrating the gas-liquid interface by combining the Immersed Boundary Method and the Level Set Method was presented. A new method of satisfying the boundary condition at the Lagrange points near the gas-liquid interface with high accuracy is described. After validating of tracing method of the gas-liquid interface by calculated result on sloshing in rectangular tank, it is presented that calculated result of the Strouhal number and distribution of time-mean velocity in wake of a circular cylinder agrees to experimental result with reasonable accuracy. Finally, calculated results of vortex pattern induced around a horizontally-oscillating vertical circular cylinder in stationary fluid under the condition of the Keulegan-Carpenter number = 9 and the Reynolds number = 1,000 is presented.

DOI： https://doi.org/10.2208/kaigan.73.I_865

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

It is thought that even very slow flow may be useful for environmental improvement of closed watersheds. This study aims to quantitatively evaluate seawater conduction to improve the environment of the Doi River, which is a part of the old moat and therefore is a river without flow. The field survey was carried out. After parameter tuning based on the field survey, a numerical calculation using the ecological model which can treat circulation of nutrients, organic carbon, oxygen, oxygen demand units and so on. It is presented that the effect of promoting slow flow and oxygen concentration on the profile of nutrient and oxygen demand units and oxygen in the sediment material.

DOI： https://doi.org/10.2208/kaigan.73.I_1333

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

In order to take countermeasures against salt damage of pier superstructure economically and efficiently, it is indispensable to clarify the wave conditions of splash generation at the vertical wall, and to grasp the characteristics of the splash. Using a series of images capturing splash generation process by a high speed camera, characteristices of splash such as the number of droplet, diameter and splashing velocity of each splashing speed, and so on are measured by the PIV and PTV technique and the relationship between splash and wave characteristics was investigated.

DOI： https://doi.org/10.2208/kaigan.73.I_835

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Simulation results of microscopic flow through porous media used Immersed Boundary method have been validated by comparison with previous experimental studies about the macroscopic pressure drop during passing porous media, the drag force acting on sphere body and so on. The constant rate of pressure drop in case of regular arrangement of porous media members shows suitability of conventional macroscopic method. However, the heterogeneity of pores caused by absence of a member of porous media would induce the difficulty of application of the conventional model. We discussed about the evidences of its difficulty by showing the pressure drop distribution inside porous media, the drag coefficient acting on each porous members, and the distribution of sectional average of intrinsic velocity in porous media.

DOI： https://doi.org/10.2208/kaigan.73.I_877

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

The flow induced by an horizontally-oscillating circular cylinder in stationary fluid was measured by the PTV technique and the relationship of turbulent flow and mean flow was investigated on the basis of the measured data. Transverse velocity of time-mean flow was large in the area that vortexes shed from a circular cylinder distributed. Although turbulent intensity was small in the area that vortexes shed from a circular cylinder did not distribute, the one was large in the area that vortexes shed from a circular cylinder distributed. In the area that time-mean turbulent energy was large, transverse velocity of time-mean flow was also large. It was suggested that turbulence induced by vortexes shed from a circular cylinder contributed to occurrence of mean flow generated around a circular cylinder.

DOI： https://doi.org/10.2208/kaigan.72.I_919

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

A numerical simulation model, which can calculate spread of inundation area on the ground and in the space of subway track by a severe storm surge and river flooding simultaneously, is developed and described in detail. Based on the calculation results, quantitative analysis of characteristics of simultaneous occurrence of inundation due to storm surge and river flooding are presented. Moreover, evacuation activities appropriate to occation of water disaster are also reffered.

DOI： https://doi.org/10.2208/kaigan.72.I_1645

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Authors have been developed a wave generation system using the vertically slotted breakwater and savonius-type water mills for several years. It has been already found from a series of a hydraulic experiment that the wave generation system have a superior wave attenuation function for wide range wave frequency rather than the present breakwater and that rotational velocity of a water mill can be estimated by using water velocity through a slit. However, the knowledge for the irregular wave has never been obtained at all. Hence, in order to obtain the knowledge for the irregular wave, hydraulic experiment was carried. It is found out that attenuation fuction will be superior by introducing water mills into the chamber. The estimation formula of the power of a water mill from waves is also introduced.

DOI： https://doi.org/10.2208/kaigan.72.I_1537

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

The measure against erosion of sandy beaches on the ocean is one of urgent national issues in view of the predicted sea level rise. Some of the authors have been studied a permeable breakwater with slotted walls supported by piles for last several years. Although the characteristics of wave attenuation of the breakwater with vertical slits has been examined by numerical calculation so far, enough validity has not been verified yet. In this study, comparison between calculated results by CADMAS-SURF/3D and experimental results on wave attenuation and flow in the visinity of the permeable breakwater is presented. As a result, it is shown that the CADMAS-SURF/3D is a useful tool to design the permeable breakwater in practical use. According to the results of the calculation and PIV measurements, it is implied that upward flow in front and back of the breakwater will be direct relation with local scour and the vertical circulation flow in the chambers of the permeable breakwater will affect sand transfer.

DOI： 10.2208/kaigan.72.I_901

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Renewable energies as substitute energy of nuclear power get much attention in not only Japan but also the world. Authors focus on the wave energy and have developed a wave power generation system using a vertical slotted breakwater with watermills installed in the chamber. From view point of the practical realization, it is necessary to estimate electrical power obtained by the watermill and power generation cost with enough accuracy as possible as we can. In the previous work, authors developed the experimental formulation between rotation rate of watermill and velocity amplitude through a vertical slit of the breakwater. In this paper, effect of scale of laboratory experiment was investigated through a series of experiments in different scale. Based on the experimental results, the formulation was modified so that the power obtained from wave by a watermill may be obtained with enough accuracy.

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

In this study, we aimed to derive the criterion of splash generation by wave acting on an impermeable vertical wall using hydraulic experiments and numerical simulations, in order to estimate the salt supply to port and harbor structure in close proximity to the surface of the sea. We found that the criterion of splash generation can separate into two different forms of splash generation using the maximum of vertical acceleration of water mass rising along vertical wall.

DOI： https://doi.org/10.2208/kaigan.71.I_853

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Authors have developed a wave power generation system using a vertical slotted breakwater with water mills in the chamber. It has been already shown that the wave absorption function of the wave power generation system is superior than a vertical slotted breakwater without watermills. In this study, reaeration capacitance of the wave power generation system is investigated on the basis of experimental results and previous research knowledge. It is presented that the reaeration capacitance of the wave power generation system can be estimated by experimental formula for a vertical slotted breakwater with wave reflection coefficient. It is presented that the reaeration capacitance of the wave power generation system can be estimated by experimental formula for a vertical slotted breakwater with wave reflection coefficient.

DOI： https://doi.org/10.2208/jscejoe.71.I_1023

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

We developed a new wave power generation system installed in a slit type breakwater. This system has great advantages of no requirement of sea surface affecting on shipping route or fishing ground. In this system, accelerated flow from the slit of the breakwater drives waterwheels. In this study, the output power of the waterwheels was measured using a 1/12 reduced scale model to examine the optimal condition of type, diameter and mounting configuration of the waterwheels. Scaling law for estimating real scale output power from the reduced scale experiment was also examined by numerical simulation. A single mounted crossflow waterwheel achieved the maximum output power when its diameter is 1.5 times the width of the slit. Output power was predicted to be proportional to 3.5th power of scale and the square of wave height.

DOI： 10.11395/jjsem.15.s26

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

 The properties of flow and free-surface oshillations induced by osillating circular cylinder arrays in stationary fluid were investigated by hydraulic experiment. Not only longitudinal sloshing but also transverse sloshing were observed depending on the oscillation conditions of circular cylinder arrays. Longitudinal sloshing occured when the freaquancies of circular cylinder arrays nearly equaled to the natural longitudinal sloshing freaquancies of a rectangular tank. The largest free-surface displacement occured when longitudinal sloshing occurred. The flow structures were generated and transverse turbulent intensity increased around circular cylinders by transverse sloshing occurrence.

DOI： 10.2208/kaigan.71.I_877

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Because of cost reduction for construction and safe utilization of coastal zone and so on, authors have proposed a wave-power generation system which equips Savonius type watermill in the chamber of a vertical-slotted breakwater. In this paper, effect of equipment of watermill in the chamber on reflection function of the breakwater was investigated in detail by conducting systematic laboratory experiments. Based on the experimental results, rate of rotation of watermill was formulated as a function of water particle velocity amplitude through a vertical slit. Further estimation methodology of a primary transformation from wave energy was presented.

DOI： https://doi.org/10.2208/kaigan.70.I_1296

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Obtaining knowledge of characteristics of splash generated by wave impact on a concrete construction in ports and harbors is one of significant research topics for highly effective protection of the structure from salt damage. In this study, the generation process of splash by wave impact on vertical wall was captured by high-speed cameras in a laboratory flume with pure water. Using PIV and PTV techniques, spatial location, diameter, and velocity of each splash particle were measured. Further, it was shown that distribution of splash diameters was formulated by the Gompertz curve with two parameters as the Weibull and the logarithmic function of splash diameter. Moreover, mean velocity and mean direction of each diameter of splash were also presented.

DOI： https://doi.org/10.2208/kaigan.70.I_946

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

A floating-type evacuation shelter from tsunami is the facility which is swepted in tsunami. Therefore, for establishment of the shelter on site, it is an important task to predict motion of the shelter with accuracy in terms of strength for tsunami fluid force and safety of evacuees. In this study, a numerical model for prediction of transitional and rotational motion of the shelter is presented. According to comparison with laboratory experimental results, calculated results on transitional and rotational motion reasonably agree with experimental ones with accuracy.

DOI： https://doi.org/10.2208/kaigan.70.I_901

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

A new type wave power generation system is proposed to be installed in a vertical slit type breakwater. The merits of the system are listed as follows, (i) no occupation of the sea surface, (ii) maintenance facility, and (iii) high energy efficiency by using accelerated flow from the slit of breakwater. In this study, several kinds of water wheels were examined to be installed in a model wave breaker with 1/12 scale ratio to the actual system. The experimental results show that the crossflow type has a higher performance. Ina addition, a bending plate type generator was examined to achieve higher efficiency. When the elastic plate is bent by the drag of wave, a tension appears and a wheel and axle is rotated. The performance of bending plate generator is examined under various experimental conditions. The output per occupied sea area is expected as 23,500(W/m^2) in the real system.

DOI： https://doi.org/10.11395/jjsem.13.60

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

As an urgent and temporal evacuation facility from tsunami, a floating-type evacuation shelter has been proposed. In order to understand translational and rotational motion of the shelter after tsunami attacks, hydraulic experiment was carried out. On the basis of experimental results, the relationship of translational and rotational motion of a shelter and wave property is presented. A numerical model for prediction of motion of a shelter is presented. According to comparison with experimental results, calculated results on translational and rotational motion agree with the order on experimental ones. It is found that improvement of the presented model is acquired for more accurate prediction of motion of a shelter.

DOI： https://doi.org/10.2208/jscejoe.70.I_319

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

For the purpose of using wave energy as a renewal energy, a wave power generation caisson with wave absorb function is being developed for last several years. In this paper, a wave power generation caisson which consists of impermeable vertical water and an array of savonius-type watermills is proposed. Energy acquisition performance from wave energy and wave attenuation ability were examined by conducting laboratory experiment. Experimental results on the effect of diameter of the watermill, the distance between impermeable wall and the center of watermills, and load torque on them are presented.

DOI： https://doi.org/10.2208/jscejoe.70.I_85

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

For the establishment of the management method of port and harbor facilities which are severely deteriorated ion by chloride damage, quantitative knowledge of spray when wave impacts on the facilities such as a vertical wall and landing pier. In this study, the process of generation and scatter of spray was taken in pictures by using high speed cameras. The characteristics of spray such as diameter of each spray, number of generated spray, splash velocity, splash direction and so on were analyzed by a developed new algorithm of analyzing captured images.

DOI： https://doi.org/10.2208/jscejoe.70.I_546

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

The internal and external fluid flows induced by oscillatory flow over a porous medium were measured by the Particle Tracking Velocimetry (PTV) with matching the refraction index method using two high-speed cameras. The characteristics of spatial variance of velocity components were shown in detail with the time phase variance. Further, the properties of the turbulent quantities such as turbulent kinematic energy and the Reynolds' stress were presented and the relationship among the turbulence properties, the Reynolds' number, and the KC number was discussed.

DOI： https://doi.org/10.2208/kaigan.69.I_41

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

In this study, a new type breakwater with a submerged circular cylinder array was developed. Laboratory experiments were carried out for investigation on effect of the height of submerged circular cylinder array on wave absorb function. Experimental results were compared with theoretical solutions. For the other type of a new breakwater with rotatable circular cylinder array, the characteristics of wave absorption were investigated.

DOI： https://doi.org/10.2208/kaigan.69.I_996

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

In order to investigate interaction between upper and inside flow of a porous medium, the microscopic structure of upper and inside flow of the porous medium placed in oscillatory flow was measured by the Particle Tracking Velocimetry (PTV) with the refractive index matching method. The strong shear flow was observed in the vicinity of the porous medium and the depth of shear flow varied with the phase of the oscillatory flow. The depth of non-dimensional shear flow was almost constant and independent with the Reynolds number. Besides, the phase difference of oscillatory flow between upper and inside flow of the porous medium was observed.

DOI： https://doi.org/10.2208/kaigan.69.I_36

Publishing type：Research paper (scientific journal)  

   A new type of wave power generation system is proposed to be installed in a vertical slit type breakwater. The merits of the system are listed as follows. (i) no occupation of the sea surface, (ii) maintenance facility, and (iii) high energy efficiency by using accelerated flow from the slit of breakwater. In this study, several kinds of water wheels are examined to be installed in a model wave breaker with 1/12 scale ratio to the actual system. The experimental results show that the drag type water wheel (Savonius wheel) has a higher performance compared with the lift type (Darius wheel), since the latter is not accelerated sufficiently during relatively short period of the sea wave. Based on the result that the drag type is favorable, a new generator is proposed to perform higher efficiency. An elastic rectangular plate connected to a wheel and axle via a string is set in the water. When the wave drag bends the plate, a tension appears in the string and it rotates the wheel connected to a generator. The performance of bending plate generator is examined under various experimental conditions. The results show that a soft textile with zero elasticity has the highest performance. The output per occupied sea area is expected as 23,500(W/m²) in the real system, which is much higher than other types of generators treated in literatures.

DOI： 10.11395/jjsem.13.60

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Numerical simulation and field investigation were carried out to examine reproducibility of thermal stratification using Regional Ocean Modeling System. Water temperature distribution was measured in enclosed water area with weather information. As a result of numerical simulation, it is found that fluctuation of thermal stratification such as destruction caused by fierce wind and development caused by solar radiation can be reproducible. Furthermore, according to calculation results of kinematic viscosity coefficient, it was indicated destruction of thermal stratification was strongly influenced by wind stress.

DOI： https://doi.org/10.2208/kaigan.68.I_941

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Numerical simulation was carried out to evaluate effect of urban heat release into an enclosed sea on the water temperature. To improve the condition of releasing the heated effluent, the resolution near release point was made higher using two-way nesting method. As a result, it is found that the effect was not influenced by only conditions of release but tidal range, tidal elevation, and wind condition. Moreover, it is found that sea surface temperature in Osaka Bay strongly depends on wind stress.

DOI： https://doi.org/10.2208/kaigan.68.I_1146

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

In order to predict turbidity flow induced by backfill using a vertical pipe, a numerical model has been developed. As a result of analysis on outflow condition from a dredged trench of the turbid water by the developed model, turbid water spreads out of a dredged trench when its thickness in front of the wall is more than 80 percent of height of the wall. Further, water including sulfide and oxygen-poor water in a dredged trench outflow anytime turbidity mass outflows from a dredged trench. In addition, it is figured out that impact to surrounding sea areas by the back-fill can be controlled by the sediment dumping time interval.

DOI： https://doi.org/10.2208/kaigan.68.I_751

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Field surveys were carried out to clarify the effect of geographical features and currents on the distribution of green-tide forming seaweed, Ulva ohnoi at the artificial tidal flat of Hannan Second District in 2011-2012. Thalli of Ulva accumulated on the northern part of the flat due to the tidal current on the flood tide. In contrast, they did not move from the north to the south of the flat because of the slow current on the ebb tide. Wind-driven currents also acted as a factor for the accumulation of Ulva on the flat. The water route was thought to play an important role on the accumulation or dispersion of Ulva at the artificial tidal flat of Hannan Second District.

DOI： https://doi.org/10.2208/kaigan.68.I_1186

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Water temperature distribution in enclosed water area, especially from water surface to 0.5m under water surface, was measured with weather information, wind, solar radiation. Seasonal change of vertical thermal distribution including violent weather effect is presented.Based on the measurement data, latent heat flux and sensible heat flux are estimated. Moreover thermal diffusivity in the water surface layer with 0.5m depth is evaluated. Finally, thermal flux between water surface and atmosphere is discussed with considering thermal supply from deeper water to water surface.

DOI： https://doi.org/10.2208/jscejoe.68.I_929

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

 A numerical model which had been already developed by authors for understanding a characteristic of turbidity flow induced by dumped sediment through a vertical pipe is improved by introducing a modified Smagorinsky turbulence model. According to comparison with a laboratory experimental results, calculated results reasonably agree with experimental ones. As a result of parametric analysis by the developed model, horizontal velocity and momentum of turbidity mass on the bottom can be controlled by initial sedimentation load. In addition, it is figured out that thickness of turbidity mass on the bottom can be controlled by the clearance between the vertical pipe and water bottom.

DOI： 10.2208/jscejoe.68.I_396

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

A series of laboratory experiment was carried out in order to examine the effect of wave-dissipating section on wave reflection characteristics of a vertical caisson covered with artificial blocks. Based on the experimental results for regular wave, two simple estimation equations of reflection coefficient were derived. One equation was represented as a function of wave steepness and relative wave height. The other was represented as a function of offshore wave length, the length of the section of wave-dissipating blocks which still water surface crossed, and water depth.

DOI： https://doi.org/10.2208/jscejoe.67.I_130

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

From view point of operation and maintenance, it is a very important issue to survey durability of salt corrosion of coastal structures. Although accurate prediction of quantity of sea spray which attaches surface of coastal structures, the generation process of sea spray when waves attack the structures such as a pier and a sea wall has not been known yet. In this study, laboratory experiments were carried out by using three high-speed cameras to capture images of generation process of spray when regular waves attack an impermeable vertical wall on 1:30 slop. From every captured image, diameter and location of each spray and the number of generated spray were obtained.
According to experimental results, it was found that the number of generated spray had a peak until t#U*=0.15 after waves attacked a vertical wall and that the number of spray depended on wave conditions. The time when the number of spray began to increase and the increase rate also depend on wave parameters. The mode value of diameter of generated spray distributed between 0.002m to 0.003m, which didn't depend on wave conditions.

DOI： https://doi.org/10.2208/jscejoe.67.I_673

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

In backfilling a dredged sea bed pit, reduction and containment of turbidity by dumped sediment are strongly required. In this study, an attachment device to a vertical pipe for reducing generation of turbidity was developed. In the experiments, flow velocity induced by dumped sediment into a vertical pipe and distribution of turbidity were measured in detail. It was shown by laboratory experiments that developed device can reduce velocity and thickness of turbidity cloud moving on the bottom. Moreover, a field experiment using a prototype device in a construction site was carried out. Based on the measured time-series data of velocity and turbidity, effectiveness of the developed device was presented.

DOI： https://doi.org/10.2208/jscejoe.67.I_703

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Abstract
This study aims development of wave power generation system using wave energy in coastal zone. A wave power generation system using a vertical slit type breakwater widely used in Japanese ports and harbors is proposed by installing an improved Savonius windmill in a chamber of the breakwater. Laboratory experiment was carried out to examine the characteristics of power generation by measurement of the rotational speed and the torque of the windmill. According to the measurement results, the relationship between obtained power and wave condition was discussed. The effect of installing the windmill in a chamber of the breakwater on wave reflection was also discussed.

DOI： https://doi.org/10.2208/kaigan.67.I_1231

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

From view point of operation and maintenance, it is a very important issue to survey durability of salt corrosion of coastal structures. Although accurate prediction of quantity of sea spray which attaches surface of coastal structures, the generation process of sea spray when waves attack the structures such as a pier and a sea wall has not been known yet. In this study, conditions of sea spray generation which waves dashing against a vertical wall were found out by laboratory experiments and numerical simulation. Although it is known that the Weber number takes part in the generating mechanism of sea spray, the Ursell number might be used as one of the conditions of sea spray generation. It was re-understood well the most predominant factor as the condition of sea spray generation was the collision velocity of water to a vertical wall.

DOI： https://doi.org/10.2208/kaigan.67.I_701

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

A laboratory experiment using the water of the Doi river was carried out to propose a reaction model of hydrogen sulfide and dissolved oxygen. Effective supply method of oxygen-rich water into the river bottom was investigated for the purpose of remediation of severe hypoxic condition through a series of experiments using a density flow model combined with the proposed reaction model. It was found that hydrogen sulfide of bottom layer mixed by induced flow by density difference and reduced by oxidation reaction. Further, it was found that water supply from multiple points was effective for wide improvement of river water under the same total amount of supply water.

DOI： https://doi.org/10.2208/kaigan.67.I_1096

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

A float-type evacuation shelter has ever been proposed as one of urgent evacuation facilities by one of the authors. In this study, a new shelter covered by a sphere shell was proposed in order to control rotation of evacuation space for refugee. A series of hydraulic experiment was carried out to understand motion of the outer spherical shell and inner shelter. The outer shell had been kept rotating immediately after tsunami attack. In contrast, the inner shelter rotated once, but reverted back to the initial condition. The possibility of control of rotation velocity of the inner shelter by the weight was implied.

DOI： https://doi.org/10.2208/kaigan.67.I_751

Publishing type：Research paper (scientific journal)  

A new wave power generation system is proposed. Although existing wave power generation systems construct or float their facilities on sea, occupation of sea surface is restricted severely in Japan because of safety ensuring of ship course and securement of fishing grounds. To eliminate this problem, a new wave generation system has been developed. The system includes its facility inside a type of breakwater that is growing popular lately. The breakwater has water chambers for vanishing waves and water flow in/out to the chamber through the slits. The vortex produced behind the slits decay wave motion. In proposed system, a Savonius water mill was located behind the slits and was driven by reciprocating water flow. The generation power in this system was measured using a 1/12 scale model and practical realization of this system was proved by the measurement.

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：International journal  

Oxygen consumption by bottom sediment is modeled based on field investigation in a eutrophied port and harbor through a whole year. Based on measured sediment oxygen consumption flux using a chamber and a dark bottle with fluorescence type oxygen sensors, biological and physical-chemical oxygen consumption processes are modeled with water temperature and dissolved oxygen concentration near the sea bottom. It is presented that these factors can be estimated by water temperature and dissolved oxygen above the sea bottom. Through modeling sediment oxygen penetration depth is a useful parameter to represent sea bottom environment as a remediation. Further, estimation method of oxygen penetration depth is improved to take into the change of the dissolved oxygen above sea bottom consideration.

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Using the Immersed Boundary Method with Physical Virtual Model proposed by Lima e Silva et al., characteristics of unidirectional flow through circular cylinders is investigated. Calculation result on a pressure drop through circular cylinders is compared with the empirical formula by Ergun. Transition of flow pattern through circular cylinders with increase in the Reynolds number is presented. In addition, spatial and time variation of fluid force acting on each cylinder is presented.

DOI： https://doi.org/10.3811/jjmf.24.689

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Authors have developed a new particle tracking velocimetry using path-line images without respite of exposure. A new detection method of coordinate of end-points path-lines is proposed in this paper. It is achieved by adding hue to the information of gray scale image captured by two cameras. Validation of the method is examined using artificial images. Further an application result of the method to measurement of 3D fluid motion induced by ascending spheres is presented.

DOI： https://doi.org/10.3811/jjmf.24.665

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Oxygen consumption by bottom sediment in a eutrophied port and harbor is modeled based on field investigation. The model consists of factors of biological contribution and chemical-physical contribution. It is presented that these factors can be estimated by water temperature and dissolved oxygen above the sea bottom. Through modeling sediment oxygen consumption it is found that a penetration depth of oxygen is a useful parameter to represent sea bottom environment as a remediation. Further, estimation method of penetration depth of oxygen is improved to take into the change of the dissolved oxygen above sea bottom consideration.

DOI： 10.2208/kaigan.66.1031

CiNii Article

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

In ports and Harbors, hypoxic or anoxic water has occurred frequently at the sea bottom. In this study, we carried out a field experiment for supplying surface water with oxygen to the bottom of sea by using surface water supplying device. We supplied surface water to the bottom of sea by using the surface water supplying device in the actual sea under hypoxic condition and we measured water quality profiles near the device. In this paper, we examined the improvement effect on sea bottom environment by surface water supplying. Furthermore, we discussed about the flow pattern of water which was supplied to the bottom of sea by conducing numerical calculations.

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

In order to get knowledge of sediment oxygen consumption in a eutrophied port through a whole year, field investigation on oxygen consumption flux by the sea bottom was carried out using a chamber and a dark bottle with fluorescence type oxygen sensors. Based on the measurement data, biological and physical-chemical oxygen consumption processes are modeled with water temperature and dissolved oxygen concentration near the sea bottom. It is shown that the oxygen penetration depth can be a useful index which represents a restoration degree of sea area under low or no dissolved oxygen concentration. It is also shown that the presented sediment oxygen consumption model can predict the change of the oxygen consumption by oxygen supply with reasonable accuracy.

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

The stratification of upper layer of coastal water can be regarded as an unused energy source in summer. The coastal water has large capability to store the urban heat owing to the heat capacity difference between the air and water. The estimated urban heat over Sumiyoshi ward in Osaka is equivalent to 10 m³/s warm water if we allow 7 degree water temperature increase from stagnant environment. The numerical simulation of the urban heat release into coastal zone is performed. The larger warm water discharge gives absorption effect of short wave radiation from the atomsphere to the ocean due to enhancement of vertical mixing of upper occean.

DOI： 10.2208/kaigan.66.1296

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

Abstract
In order to predict fluid motion induced by sediment dumped into a vertical pipe, a numerical model is developed. The numerical model is based on fundamental equation of incompressible fluid with the Boussinesq approximation and the Volume Of Fluid method is applied to trace water surface in a vertical pipe. According to comparison with laboratory experimental results, calculated results reasonably agree with experimental ones in qualitatively. The estimation results by the developed model on thickness and progressive velocity of turbidity mass on the bottom are presented with maximum ambient fluid velocity.

DOI： 10.2208/kaigan.66.751

CiNii Article

Publishing type：Research paper (scientific journal)   Kind of work：Joint Work  

To understand oxygen consumption characteristics of sediment for the case of oxygen supply to the bottom of sea under the hypoxic condition, we carried out a laboratory experiment by using sediment and artificial-seawater. It is found that the oxygen consumption pattern of sediment is changing while sediment consumes oxygen. Immediately after oxygen supplying, dissolved oxygen of seawater was consumed by the chemical reaction in the sediment. And then dissolved oxygen consumed by the biological reaction.

DOI： 10.2208/kaigan.66.1196

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

The modeling of turbulence for the flow passing through a porous media is analyzed experimentally by using a priori tests. Velocity field inside and around a porous media is obtained with PTV. Two turbulence models, linear eddy viscosity model and nonlinear model, are tested on different Reynolds number conditions. There is a high correlation in the turbulent stress and the nonlinear velocity gradient. The applicability of the latter model is higher than the former. The model coefficient doesn't depend on the Reynolds number and the size of the spatial average area.

DOI： 10.2208/kaigan.66.771

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Kind of work：Joint Work   International / domestic magazine：Domestic journal  

There is few research on fluid force acting on solids and turbulent flow in a pore of porous media because of the difficulty of measurement in experiments. In order to get fundamental knowledge of them, 2-D unidirectional fluid flow is investigated numerically using the Immersed Boundary method, which rigorously satisfies with the boundary condition on the solid surface with Cartesian grid and Lagrangian grid. Calculation results on pressure drop through circular cylinders reasonably agree with experimental formula by Ergun. In addition, fluid force acting on each cylinder, which varies markedly in time and space, is also presented.

DOI： 10.2208/kaigan.66.761

CiNii Article

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

CiNii Article

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

CiNii Article

Publishing type：Research paper (scientific journal)  

DOI： 10.3154/jvs.29.215

CiNii Article

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

The characteristics of bubble entrainment process in the surf zone are discussed. The two-phase flow measurements using two-dimensional imaging technique for bubble measurements, so called Bubble Tracking Velocimetry (BTV) were conducted in the laboratory wave tank. The horizontal and vertical distributions of void fraction and characteristic bubble size were measured and analyzed in detail. The relationship between the void fraction and wave energy dissipation are proposed for the surf zone breaking waves.

DOI： 10.2208/kaigan.65.96

CiNii Article

Publishing type：Research paper (scientific journal)  

A new algorithm of a 3D particle tracking velocimetry, 3D-PLCV is developed. The significant feature is the use of images capturing path lines without any blind duration between sequential images. Hence, particle matching becomes very easy by connecting path lines in sequential images. Further, use of information of connected path line is useful to restrain generation of ghost tracers in stereo-matching. After description of details of the algorithm of the 3D-PTV developed in this study is presented, validity of the 3D-PTV is shown using artificial images. Finally, measurement result of fluid flow in pore of porous media by the developed PTV is presented.

DOI： 10.2208/kaigan.65.1461

CiNii Article

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

For effective restoration of enclosed coastal zone under anoxic environment such as Osaka bay, it is necessary to understand characteristics of oxygen consumption by the bottom sediment of ports and harbors. In this study, field measurements of the oxygen consumption rate were carried out during the year in a harbor. Seasonal variations in characteristics of the oxygen consumption by sediment were presented and the formulation of oxygen consumption by bottom sediment was attempted.

DOI： 10.2208/kaigan.65.1051

CiNii Article

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Turbulence in pores of porous media in oscillating flow was measured by using a Particle Tracking Velocimetry with the Refraction index matching method. Relationship between turbulent energy and oscillating flow characteristics such as the Reynolds number and KC number is presented. Variation of generated turbulent energy in pores and vicinity of porous media in a phase is presented in detail.

DOI： 10.1299/jsmemecjo.2008.2.0_235

CiNii Article

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

The characteristics of bubble entrainment process owing to vertical circular jet at the water surface are discussed. The two-phase flow measurements using imaging technique for two-dimensional bubble measurements, so called Bubble Tracking Velocimetry (BTV) were conducted in the laboratory. The dependence of the Froude number and salinity on the air bubble statistics beneath the water surface are discussed both downward and rising bubbles. The clear dependence of the Froude number on bubble size distribution is obtained through the experiments.

CiNii Article

Publishing type：Research paper (scientific journal)  

There are several turbulence models and stability functions for thermal stratification for ocean circulation modeling. These models have been verified in the open ocean but are verified in depth limited conditions. The two different turbulence models and three different stability functions are used for coastal water modeling. The circulations of coastal water is influenced by both vertical turbulence schemes and stability functions. The Mellor-Yamada level 2.5 closure model gives better agreement for tidal circulations than generic scale turbulence model.

CiNii Article

Publishing type：Research paper (scientific journal)  

CiNii Article

Publishing type：Research paper (scientific journal)  

An image velocimetry technique for measuring fluid motion of liquid-solid flow with high particle density is developed and presented. The new technique, which obtains velocities and directions by connecting path lines of tracers in sequence images captured by high speed cameras, is classified into a kind of particle tracking velocimetry. Detail of the algorithm of the developed image velocimetry, called path line connecting velocimetry (PLCV), is presented. Some results of measuring liquid-solid flows induced by dispersion phase with high concentration are presented.

DOI： 10.3811/pmfr.2.141

CiNii Article

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

The effect of Reynolds number on the properties of turbulence generated by a porous media was investigated by a hydraulic experiment. Velocity field inside and around the porous media was measured with a high resolution temporally and spatially using the Super-resolution KC method and a refractive index matching method. It is presented that some properties of turbulence can be normalized by a characteristic velocity and a diameter of the sphere which constitute the porous media.

DOI： 10.2208/proce1989.54.801

CiNii Article

Publishing type：Research paper (scientific journal)  

The stratification of upper layer of coastal water can be regarded as an unused energy source for heat pump systems near coastal area in the summer. This study examines feasibility of heat pump system for coastal area using a cold water mass beneath the thermal stratified upper water. The field observations for thermalcharacteristics in the harbor were conduced through the summer season. The characteristics of stratified water are investigated by the field observations and numerical simulations. The breakdown of stratification is also examined by the numerical simulations for the heat pump system using the coastal water.

DOI： 10.2208/proce1989.54.1316

CiNii Article

Publishing type：Research paper (scientific journal)  

The present paper dealt with the distribution and dynamics of oxygen at the artificial tidal flat of Hannan Second District, Osaka Bay.<BR>Oxygen-deficient waters were found on September 2005 and July 2006 at the bottom of shallow area of the artificial tidal flat where ground levels were from D. L.-2.3 to D. L.-1.9m. Photosynthesis of phytoplankton and seaweed played an important role on the dynamics of oxygen at the artificial tidal flat. Release of oxygen by phytoplankton changed depending on photon flux density, while dominant seaweed, Ulva sp. showed active photosynthesis in spite of low photon flux density. Oxygen consumption by respiration of Ulva sp. promoted hypoxia at night at the ground level of ca. D. L.-1. Om of the artificial tidal flat.

DOI： 10.2208/proce1989.54.1261

CiNii Article

Publishing type：Research paper (scientific journal)  

We have developed a new breakwater, named as VCF-Breakwater for generating vertical circulation flow which transports oxygen-rich surface water into the anoxic sea bottom. In this study, the behavior of the vertical circulation flow was measured using dye and PIV technique and salinity profiles were also measured by salnometers. Based on the experimental results, the effectiveness of the VCF breakwater is discussed.

DOI： 10.2208/proce1989.54.1236

CiNii Article

Publishing type：Research paper (scientific journal)  

DOI： 10.1088/0233/17/6/025

Publishing type：Research paper (scientific journal)  

In this study, we investigated the nitrogen budget with fine weather and factors of preservation at the natural tidal flat near the city. Furthermore, we examined the amount of the inflow load to the tidal flat at rainy days. As results, the Ulva and Benthoses contribute for the nitrogen fixation in the tidal flat. The runoff water load is relatively little as the amount of inflow load to the tidal flat. On the estuary tidal flat in wakayama are controlled by the amount of the treated water load from the wastewater treatment plant and the amount of the pump water load up from the tidal flat

DOI： 10.2208/jscejg.62.41

CiNii Article

Publishing type：Research paper (scientific journal)  

In most of coastal zone, dissolved oxygen near the sea bottom decreases in summer season. It is important to supply oxygen to the anoxia sea bottom for habitat environment of benthos. A new breakwater for generationg vertical circulation flow (VCF) has developed for transporting oxygen-rich surface water to the sea bottom. Effectiveness of the breakwater on generating the flow has been already verified by experiments and numerical calculations. In this study, for evaluating the reaeration capacity of VCF, mass transfer coefficient of oxygen was measured by laboratory experiment. And, the relationship between reaeration characteristics and hydraulic characteristics of VCF were examined by using a numerical model.

CiNii Article

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

Author has already developed a numerical model for calculating liquid-solid flow by using the Distinct Element Method for analyzing particle motions and the Volume of Fluid Method for tracking water surface. In this study, validity of the numerical model is checked by comparing calculated and experimental results on deposition configuration of particles dumped into waters. Subsequently variation of configuration on the bottom with number of dumping particles is investigated by conducting numerical experiments using the model.

CiNii Article

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

海岸工学文集

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

屈折率整合法を用いた画像計測手法によって, 多孔質体の間隙部およびその上・下流部に及ぶ大領域を対象とした流速場を高時間解像度で計測し, さらに, 多孔質体の異なる断面で計測を行うことによって, 多孔質体内流れの準3次元構造の把握を試みた. 計測結果に基づいて, スペクトル, 乱流諸量を算定し, 流れの時・空間的変動特性について検討を行った. その結果, 断面毎に値の差異は見られたが, 分布形状は類似しており, 全断面平均値として多孔質体内部の乱流諸量を求めることができた. また, 異なる渦動粘性モデルを用いて多孔質体内外の渦動粘性係数を推定し, 定量的な比較を行った.

DOI： 10.2208/proce1989.53.761

CiNii Article

Publishing type：Research paper (scientific journal)  

CiNii Article

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

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Publishing type：Research paper (scientific journal)  

Total pages：44   Responsible for pages：2  

Total pages：48   Responsible for pages：4  

Total pages：233   Responsible for pages：12  

Total pages：111   Responsible for pages：4  

Book type：Scholarly book

Book type：Scholarly book

Book type：Scholarly book

Book type：Scholarly book

Book type：Scholarly book

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Kind of work：Single Work  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Authorship：Last author   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   International / domestic magazine：Domestic journal  

Presentation type：Oral presentation (general)  

DOI： https://doi.org/10.2208/kaigan.78.2_I_625

Presentation type：Oral presentation (general)  

DOI： https://doi.org/10.2208/jscejoe.78.2_I_367

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：コングレコンベンションセンター（グランフロント大阪内）  

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

DOI： https://doi.org/10.9753/icce.v36v.structures.39

property_type：Patent 

Application no：特願2002-84636（P2002-84636） 

Announcement no：特開2003-278125（P2003-2781525A） 

Publication no：特開2003-278125（P2003-2781525A） 

大阪府立大学工学域海洋システム工学科の外部評価委員を務めた．

Audience： General public

Number of participants：50（人）

「近年の台風・大雨被害と対策」と題して、2回の講演を行った。

Audience： General public,　Company,　Civic organization,　Governmental agency

Number of participants：100（人）

Audience： General public,　Governmental agency

Number of participants：70（人）

Audience： Schoolchildren

Number of participants：100（人）

「水害と非難の流れ」についての授業

Audience： University students,　General public

Number of participants：47（人）

Audience： High school students

「課題研究」に対するアドバイス・指導・評価を行った．

Audience： High school students