Chia-Ren Chu | National Central University (original) (raw)
Papers by Chia-Ren Chu
Physics of Fluids , 2022
This study numerically investigates the interaction between two side-by-side free-falling spheres... more This study numerically investigates the interaction between two side-by-side free-falling spheres in water. The predicted S-curve falling trajectories of the spheres were verified by laboratory experiments, and the attraction-repulsion of lateral force on the vertically falling spheres is investigated to give a better understanding of the evolution of the lateral force by excluding the effect of the transverse motion. The flow pattern around the spheres reveals that the wake flows play an essential role in the fluid-sphere interaction. Then, the two free-falling spheres with transverse motion are considered to examine the interacting force and the crosswise strength of wake flows. This study attempts to explore the wake flow as the possible mechanism for the S-curve falling trajectories of two spheres. Finally, the falling processes of the two spheres are simulated in a deeper tank to inspect the falling trajectories and the reappearing flow characteristics.
Building Simulation, 2017
Natural ventilation is one of the most commonly used methods to remove air pollutants and to impr... more Natural ventilation is one of the most commonly used methods to remove air pollutants and to improve indoor air quality. This study integrates a resistance model to predict the ventilation rate and a transport model to compute the pollutant concentration in partitioned buildings. The model predictions are validated by a series of wind tunnel experiments with scale-down building models. The concentration variations of tracer gas inside the models were measured by a gas chromatography, and the external and internal pressures were determined by a multi-channel pressure scanner. The verified transport model was then applied to evaluate the influences of external wind speed, initial concentration, opening areas and interior volume on the transient concentration and dispersion time of gaseous pollutants within a two-room buildings. Results of the parametric study indicate that the dispersion time and the ratio of the maximum concentration in the adjacent room to the initial concentration of the room with the pollutant source was about 0.50-0.60, depending on the ventilation rate and interior volume.
Physics of Fluids, 2020
This study uses a two-way dynamic coupled numerical model and laboratory experiments to investiga... more This study uses a two-way dynamic coupled numerical model and laboratory experiments to investigate the interaction of two free-falling spherical particles in water. Two spheres, with identical diameters D and densities, are released side-by-side simultaneously in a water tank. The Reynolds number, based on the terminal velocity and diameter of the sphere, is Re = 1.36 × 10 4. The experimental and numerical results reveal that the falling trajectories of the spheres look like S-curves when the initial gap between the two spheres is less than 0.75 D. The numerical simulation demonstrates that the fluid pressure in the gap region is less than the pressure outside of the gap and causes the spheres to move toward each other as they fall. Then, the vortices alternately shed behind the spheres and generate a lateral force to deviate the spheres from the vertical trajectory. When the lateral distance between the two spheres is greater than 0.75 D, the interaction between the spheres becomes negligible. A similar phenomenon is also observed when one single falling sphere is very close to a vertical sidewall. The sidewall effect on the sphere's trajectory is noticeable when the gap between the falling sphere and the sidewall is less than 0.5 D. Nonetheless, the influence of a sidewall is more significant than that of an adjacent sphere.
Experiments in Fluids, 2022
This study experimentally investigates the vortex structure induced by sphere-wall collision and ... more This study experimentally investigates the vortex structure induced by sphere-wall collision and a falling sphere in a viscous liquid. The velocity fields of sphere-induced vortices were measured with refractive-index-matched materials and particle tracking velocimetry. The Reynolds number, based on the sphere diameter and the falling velocity, was in the range of 350-3200. The results revealed that the sphere-induced vortex ring was axisymmetric when the Reynolds number Re is ≤ 800. For the case of Re = 2000, the vortex structure developed into a non-symmetric flow after the sphere collided on the wall. Nonetheless, the influence of the Reynolds number on the vortex trajectory is insignificant. The moving speed of the primary vortex increases as the Reynolds number increases. In addition, the trajectories of free-falling spheres at a high Reynolds number of Re = 3200 deviate from a vertical straight line, owing to the non-axisymmetric flow field around the sphere. The experimental results presented in this work can be used to validate numerical schemes for solid/vortex interaction problems.
International Journal of Multiphase Flow, 2022
This study incorporates a hybrid Cartesian/immersed boundary (HCIB) method and the Navier-Stokes ... more This study incorporates a hybrid Cartesian/immersed boundary (HCIB) method and the Navier-Stokes equations to simulate three-dimensional vortex flows around spheres swinging and colliding in viscous fluids. The motions of the spheres were prescribed in the model, and the simulated velocities around the spheres were validated by the results of laboratory experiments. The Reynolds number computed by the sphere diameter and the maximum swing velocity was Re = 13,500. The simulation results were examined in detail to elucidate the threedimensional flows and pressure fields induced by the single swinging sphere and two colliding spheres. The evolution of the vortices can be divided into two parts: (i) Before the collision, the primary vortex ring induced by the swinging sphere grows in size, propagates obliquely downward, and eventually dissipates into turbulent flow. (ii) After the collision, the striking sphere transfers its momentum to the target sphere and another vortex ring is generated in front of the striking sphere owing to its impulsive deceleration. This vortex ring is separated from the sphere's boundary and the vorticity pattern is different from that of a single sphere case. After the collision, the target sphere upswings with almost no vortical wake behind it, as observed in the experiments.
Journal of Geophysical Research, 1994
In this paper, we present a two-way coupled moving solid algorithm with discrete element method (... more In this paper, we present a two-way coupled moving solid algorithm with discrete element method (DEM) to simulate dynamic fluid-solid interaction. This model allows obstacles moving in the multi-phase fluids to generate realistic motion for both the fluids and obstacles. We discretize the NavierStokes equation using finite volume method (FVM) for the fluid part. The volume-of-fluid (VOF) method is used to track the fluid-fluid and fluid-solid interfaces. This algorithm is useful in the fields of Engineering and Earth Sciences, such as structure collapse and landslide generated tsunamis. Examples of landslide tsunami and floating cubes are demonstrated using the algorithm.
Building and Environment, 2022
Natural ventilation of buildings can bring in fresh air, remove indoor air contaminants, and impr... more Natural ventilation of buildings can bring in fresh air, remove indoor air contaminants, and improve indoor thermal comfort. However, ventilation may also bring outdoor pollutants and/or aerosol into the buildings to affect the indoor air quality. This study uses a computational fluid dynamics model and a Lagrangian particle tracking model to investigate the transport process of outdoor particulate matter (PM) into a naturally ventilated building. The simulation results indicate that the entrance rate of outdoor PM contaminants is in the range of 7%-25%, depending on the particle size and the distance between the pollutant source and the building. The indoor concentration of PM 2.5 decreases as the external wind speed and ventilation rate increase. In other words, sufficient natural ventilation can remove indoor particulate contaminants. In addition, the deposition rates in long buildings are larger than that in short buildings, owing to the sluggish airflow inside the long buildings. This study also estimates the time scales of particle deposition and ventilation-induced advection. The results reveal that the ventilation-induced airflow dominates the removal of fine particles PM 1 and PM 2.5 , whereas the ventilation and deposition are equally important for coarse particle PM 10 .
Applied Sciences
This paper incorporates the Bingham rheology model with the Navier–Stokes solver to simulate the ... more This paper incorporates the Bingham rheology model with the Navier–Stokes solver to simulate the tsunamis excited by a slump-type landslide. The slump is modeled as the Bingham material, in which the rheological properties changing from the un-yield phase to yield phase is taken into account. The volume of fluid method is used to track the interfaces between three materials: air, water, and slump. The developed model is validated by the laboratory data of the benchmark landslide tsunami problem. A series of rheological properties analyses is performed to identify the parameter sensitivity to the tsunami generation. The results show that the yield stress plays a more important role than the yield viscosity in terms of the slump kinematics and tsunami generation. Moreover, the scale effect is investigated under the criterion of Froude number similarity and Bingham number similarity. With the same Froude number and Bingham number, the result from the laboratory scale can be applied to ...
Applied Sciences
This paper incorperates Bingham and bi-viscosity rheology models with the Navier–Stokes solver to... more This paper incorperates Bingham and bi-viscosity rheology models with the Navier–Stokes solver to simulate the dynamics and kinematics processes of slumps for tsunami generation. The rheology models are integrated into a computational fluid dynamics code, Splash3D, to solve the incompressible Navier–Stokes equations with volume of fluid surface tracking algorithm. The change between un-yield and yield phases of the slide material is controlled by the yield stress and yield strain rate in Bingham and bi-viscosity models, respectively. The integrated model is carefully validated by the theoretical results and laboratory data with good agreements. This validated model is then used to simulate the benchmark problem of the failure of the gypsum tailings dam in East Texas in 1966. The accuracy of predicted flood distances simulated by both models is about 73% of the observation data. To improve the prediction, a fixed large viscosity is introduced to describe the un-yield behavior of tail...
Journal of Earthquake and Tsunami
Energy dissipation mechamism is the key to study tsunami hazard mitigation. Numerical method is a... more Energy dissipation mechamism is the key to study tsunami hazard mitigation. Numerical method is adopted to study the interaction between bores and square cylinders. The model solves the three-dimensional Navier–Stokes equations with Large-Eddy Simulation turbulence model. The Volume-of-fluid (VOF) method is used to track the complex free surface. We focus the investigation on the effect of cylinder height on the flow field. The results show that the turbulence diffusion is the main mechanism for energy dissipation. The flow patterns are significantly different within and beyond the cylinder array. The taller cylinders cause smaller velocity magnitude in the downstream area. In addition, a larger value of velocity magnitude and vorticity near the bottom is identified in the tall-cylinder case. These unique featuers make different dissipation rates.
Journal of Hydraulic Engineering, 2016
This study integrates a large eddy simulation model to investigate the effect of a submerged rect... more This study integrates a large eddy simulation model to investigate the effect of a submerged rectangular cylinder on the hydro-dynamics of free surface flows. The simulation results are validated by the results of flume experiments. Then the numerical model is utilized to examine the influences of Reynolds number, Froude number, and blockage ratio on the flow field and the force coefficients of the deck. The simulation results reveal that the drag coefficient is dependent on the deck's Froude number and blockage ratio of the bridge deck, rather than the Reynolds number. For both subcritical and transcritical flows, the drag coefficient increases as the blockage ratio increases. However, due to the wave-induced drag, the drag coefficient of the cylinder in transcritical flows is greater than that in subcritical flows with the same blockage ratio. On the other hand, the lift coefficient is a function of the submergence ratio and the deck's Froude number. The separation shear flow on the upper side of the cylinder is constrained by the water surface when the submergence ratio h à < 2.0, and resulting in an asymmetric pressure distribution on the upper and lower sides of the deck, which subsequently generates a downward force on the bridge deck.
Renewable Energy, 2003
Wind characteristics and wind turbine characteristics in Taiwan have been thoughtfully analyzed b... more Wind characteristics and wind turbine characteristics in Taiwan have been thoughtfully analyzed based on a long-term measured data source (1961–1999) of hourly mean wind speed at 25 meteorological stations across Taiwan. A two-stage procedure for estimating wind resource is proposed. The yearly wind speed distribution and wind power density for the entire Taiwan is firstly evaluated to provide annually spatial mean information of wind energy potential. A mathematical formulation using a two-parameter Weibull wind speed ...
Advances in Water Resources, 2000
Recent Advances in Engineering Mechanics and Their Impact on Civil Engineering Practice,; pp. 519-529.
Observations on the Nature and Mechanism of the Structure of Turbulent Boundary Layers: A Survey ... more Observations on the Nature and Mechanism of the Structure of Turbulent Boundary Layers: A Survey and New Results. CR Chu, M Parlange, W Eichinger, G Katul Recent Advances in Engineering Mechanics and Their Impact on Civil Engineering Practice,, 519-529. 25 Geotechnical Engineering(CE).
ASCE, NEW YORK, NY,(USA)., 1994
The distribution of atmospheric water vapor across a step change in surface humidity (dry-wet) wa... more The distribution of atmospheric water vapor across a step change in surface humidity (dry-wet) was observed by a Lidar measurement technique under neutral atmospheric stability condition. The technique uses multiple elevation scans from a scanning water Raman-Lidar to construct a time-averaged image of the variation in water vapor concentration with height and distance. The measurements were obtained from a bare soil field in California's central valley. The growth of the vapor blanket over the wet surface was identified by the spatial ...
PROCEEDINGS OF THE CONGRESS-INTERNATIONAL ASSOCIATION FOR HYDRAULIC RESEARCH, 2001
Abstract: A finite difference predictor-corrector TVD scheme is developed for the simulation of u... more Abstract: A finite difference predictor-corrector TVD scheme is developed for the simulation of unsteady one-dimensional dam-break flows. The accuracy and robustness of the numerical scheme is verified with an analytic solution. Furthermore, a sensitivity study is carried out to investigate the efficiency and robustness of four different versions of the predictor-corrector schemes. It is found that the numerical scheme will have less computational error and higher efficiency when the direction of the predictor-corrector step ...
JWE: 日本風工学研究会誌, Oct 31, 2001
JWE: 日本風工学研究会誌, Jul 14, 2006
ABSTRACT: In this research, a mathematical model is proposed for predicting wind-induced response... more ABSTRACT: In this research, a mathematical model is proposed for predicting wind-induced response of a building with a tuned mass damper (TMD) when soil-structure interaction (SSI) is considered. It may reasonably reflect soil characteristics. Furthermore, TMDs are effective devices for reducing structural vibration. This study may help researchers to more accurately evaluate wind-induced oscillation of high-rise buildings with SSI as well as select appropriate TMDs in controlling structural response. KEYWORDS: wind-induced vibration; ...
Physics of Fluids , 2022
This study numerically investigates the interaction between two side-by-side free-falling spheres... more This study numerically investigates the interaction between two side-by-side free-falling spheres in water. The predicted S-curve falling trajectories of the spheres were verified by laboratory experiments, and the attraction-repulsion of lateral force on the vertically falling spheres is investigated to give a better understanding of the evolution of the lateral force by excluding the effect of the transverse motion. The flow pattern around the spheres reveals that the wake flows play an essential role in the fluid-sphere interaction. Then, the two free-falling spheres with transverse motion are considered to examine the interacting force and the crosswise strength of wake flows. This study attempts to explore the wake flow as the possible mechanism for the S-curve falling trajectories of two spheres. Finally, the falling processes of the two spheres are simulated in a deeper tank to inspect the falling trajectories and the reappearing flow characteristics.
Building Simulation, 2017
Natural ventilation is one of the most commonly used methods to remove air pollutants and to impr... more Natural ventilation is one of the most commonly used methods to remove air pollutants and to improve indoor air quality. This study integrates a resistance model to predict the ventilation rate and a transport model to compute the pollutant concentration in partitioned buildings. The model predictions are validated by a series of wind tunnel experiments with scale-down building models. The concentration variations of tracer gas inside the models were measured by a gas chromatography, and the external and internal pressures were determined by a multi-channel pressure scanner. The verified transport model was then applied to evaluate the influences of external wind speed, initial concentration, opening areas and interior volume on the transient concentration and dispersion time of gaseous pollutants within a two-room buildings. Results of the parametric study indicate that the dispersion time and the ratio of the maximum concentration in the adjacent room to the initial concentration of the room with the pollutant source was about 0.50-0.60, depending on the ventilation rate and interior volume.
Physics of Fluids, 2020
This study uses a two-way dynamic coupled numerical model and laboratory experiments to investiga... more This study uses a two-way dynamic coupled numerical model and laboratory experiments to investigate the interaction of two free-falling spherical particles in water. Two spheres, with identical diameters D and densities, are released side-by-side simultaneously in a water tank. The Reynolds number, based on the terminal velocity and diameter of the sphere, is Re = 1.36 × 10 4. The experimental and numerical results reveal that the falling trajectories of the spheres look like S-curves when the initial gap between the two spheres is less than 0.75 D. The numerical simulation demonstrates that the fluid pressure in the gap region is less than the pressure outside of the gap and causes the spheres to move toward each other as they fall. Then, the vortices alternately shed behind the spheres and generate a lateral force to deviate the spheres from the vertical trajectory. When the lateral distance between the two spheres is greater than 0.75 D, the interaction between the spheres becomes negligible. A similar phenomenon is also observed when one single falling sphere is very close to a vertical sidewall. The sidewall effect on the sphere's trajectory is noticeable when the gap between the falling sphere and the sidewall is less than 0.5 D. Nonetheless, the influence of a sidewall is more significant than that of an adjacent sphere.
Experiments in Fluids, 2022
This study experimentally investigates the vortex structure induced by sphere-wall collision and ... more This study experimentally investigates the vortex structure induced by sphere-wall collision and a falling sphere in a viscous liquid. The velocity fields of sphere-induced vortices were measured with refractive-index-matched materials and particle tracking velocimetry. The Reynolds number, based on the sphere diameter and the falling velocity, was in the range of 350-3200. The results revealed that the sphere-induced vortex ring was axisymmetric when the Reynolds number Re is ≤ 800. For the case of Re = 2000, the vortex structure developed into a non-symmetric flow after the sphere collided on the wall. Nonetheless, the influence of the Reynolds number on the vortex trajectory is insignificant. The moving speed of the primary vortex increases as the Reynolds number increases. In addition, the trajectories of free-falling spheres at a high Reynolds number of Re = 3200 deviate from a vertical straight line, owing to the non-axisymmetric flow field around the sphere. The experimental results presented in this work can be used to validate numerical schemes for solid/vortex interaction problems.
International Journal of Multiphase Flow, 2022
This study incorporates a hybrid Cartesian/immersed boundary (HCIB) method and the Navier-Stokes ... more This study incorporates a hybrid Cartesian/immersed boundary (HCIB) method and the Navier-Stokes equations to simulate three-dimensional vortex flows around spheres swinging and colliding in viscous fluids. The motions of the spheres were prescribed in the model, and the simulated velocities around the spheres were validated by the results of laboratory experiments. The Reynolds number computed by the sphere diameter and the maximum swing velocity was Re = 13,500. The simulation results were examined in detail to elucidate the threedimensional flows and pressure fields induced by the single swinging sphere and two colliding spheres. The evolution of the vortices can be divided into two parts: (i) Before the collision, the primary vortex ring induced by the swinging sphere grows in size, propagates obliquely downward, and eventually dissipates into turbulent flow. (ii) After the collision, the striking sphere transfers its momentum to the target sphere and another vortex ring is generated in front of the striking sphere owing to its impulsive deceleration. This vortex ring is separated from the sphere's boundary and the vorticity pattern is different from that of a single sphere case. After the collision, the target sphere upswings with almost no vortical wake behind it, as observed in the experiments.
Journal of Geophysical Research, 1994
In this paper, we present a two-way coupled moving solid algorithm with discrete element method (... more In this paper, we present a two-way coupled moving solid algorithm with discrete element method (DEM) to simulate dynamic fluid-solid interaction. This model allows obstacles moving in the multi-phase fluids to generate realistic motion for both the fluids and obstacles. We discretize the NavierStokes equation using finite volume method (FVM) for the fluid part. The volume-of-fluid (VOF) method is used to track the fluid-fluid and fluid-solid interfaces. This algorithm is useful in the fields of Engineering and Earth Sciences, such as structure collapse and landslide generated tsunamis. Examples of landslide tsunami and floating cubes are demonstrated using the algorithm.
Building and Environment, 2022
Natural ventilation of buildings can bring in fresh air, remove indoor air contaminants, and impr... more Natural ventilation of buildings can bring in fresh air, remove indoor air contaminants, and improve indoor thermal comfort. However, ventilation may also bring outdoor pollutants and/or aerosol into the buildings to affect the indoor air quality. This study uses a computational fluid dynamics model and a Lagrangian particle tracking model to investigate the transport process of outdoor particulate matter (PM) into a naturally ventilated building. The simulation results indicate that the entrance rate of outdoor PM contaminants is in the range of 7%-25%, depending on the particle size and the distance between the pollutant source and the building. The indoor concentration of PM 2.5 decreases as the external wind speed and ventilation rate increase. In other words, sufficient natural ventilation can remove indoor particulate contaminants. In addition, the deposition rates in long buildings are larger than that in short buildings, owing to the sluggish airflow inside the long buildings. This study also estimates the time scales of particle deposition and ventilation-induced advection. The results reveal that the ventilation-induced airflow dominates the removal of fine particles PM 1 and PM 2.5 , whereas the ventilation and deposition are equally important for coarse particle PM 10 .
Applied Sciences
This paper incorporates the Bingham rheology model with the Navier–Stokes solver to simulate the ... more This paper incorporates the Bingham rheology model with the Navier–Stokes solver to simulate the tsunamis excited by a slump-type landslide. The slump is modeled as the Bingham material, in which the rheological properties changing from the un-yield phase to yield phase is taken into account. The volume of fluid method is used to track the interfaces between three materials: air, water, and slump. The developed model is validated by the laboratory data of the benchmark landslide tsunami problem. A series of rheological properties analyses is performed to identify the parameter sensitivity to the tsunami generation. The results show that the yield stress plays a more important role than the yield viscosity in terms of the slump kinematics and tsunami generation. Moreover, the scale effect is investigated under the criterion of Froude number similarity and Bingham number similarity. With the same Froude number and Bingham number, the result from the laboratory scale can be applied to ...
Applied Sciences
This paper incorperates Bingham and bi-viscosity rheology models with the Navier–Stokes solver to... more This paper incorperates Bingham and bi-viscosity rheology models with the Navier–Stokes solver to simulate the dynamics and kinematics processes of slumps for tsunami generation. The rheology models are integrated into a computational fluid dynamics code, Splash3D, to solve the incompressible Navier–Stokes equations with volume of fluid surface tracking algorithm. The change between un-yield and yield phases of the slide material is controlled by the yield stress and yield strain rate in Bingham and bi-viscosity models, respectively. The integrated model is carefully validated by the theoretical results and laboratory data with good agreements. This validated model is then used to simulate the benchmark problem of the failure of the gypsum tailings dam in East Texas in 1966. The accuracy of predicted flood distances simulated by both models is about 73% of the observation data. To improve the prediction, a fixed large viscosity is introduced to describe the un-yield behavior of tail...
Journal of Earthquake and Tsunami
Energy dissipation mechamism is the key to study tsunami hazard mitigation. Numerical method is a... more Energy dissipation mechamism is the key to study tsunami hazard mitigation. Numerical method is adopted to study the interaction between bores and square cylinders. The model solves the three-dimensional Navier–Stokes equations with Large-Eddy Simulation turbulence model. The Volume-of-fluid (VOF) method is used to track the complex free surface. We focus the investigation on the effect of cylinder height on the flow field. The results show that the turbulence diffusion is the main mechanism for energy dissipation. The flow patterns are significantly different within and beyond the cylinder array. The taller cylinders cause smaller velocity magnitude in the downstream area. In addition, a larger value of velocity magnitude and vorticity near the bottom is identified in the tall-cylinder case. These unique featuers make different dissipation rates.
Journal of Hydraulic Engineering, 2016
This study integrates a large eddy simulation model to investigate the effect of a submerged rect... more This study integrates a large eddy simulation model to investigate the effect of a submerged rectangular cylinder on the hydro-dynamics of free surface flows. The simulation results are validated by the results of flume experiments. Then the numerical model is utilized to examine the influences of Reynolds number, Froude number, and blockage ratio on the flow field and the force coefficients of the deck. The simulation results reveal that the drag coefficient is dependent on the deck's Froude number and blockage ratio of the bridge deck, rather than the Reynolds number. For both subcritical and transcritical flows, the drag coefficient increases as the blockage ratio increases. However, due to the wave-induced drag, the drag coefficient of the cylinder in transcritical flows is greater than that in subcritical flows with the same blockage ratio. On the other hand, the lift coefficient is a function of the submergence ratio and the deck's Froude number. The separation shear flow on the upper side of the cylinder is constrained by the water surface when the submergence ratio h à < 2.0, and resulting in an asymmetric pressure distribution on the upper and lower sides of the deck, which subsequently generates a downward force on the bridge deck.
Renewable Energy, 2003
Wind characteristics and wind turbine characteristics in Taiwan have been thoughtfully analyzed b... more Wind characteristics and wind turbine characteristics in Taiwan have been thoughtfully analyzed based on a long-term measured data source (1961–1999) of hourly mean wind speed at 25 meteorological stations across Taiwan. A two-stage procedure for estimating wind resource is proposed. The yearly wind speed distribution and wind power density for the entire Taiwan is firstly evaluated to provide annually spatial mean information of wind energy potential. A mathematical formulation using a two-parameter Weibull wind speed ...
Advances in Water Resources, 2000
Recent Advances in Engineering Mechanics and Their Impact on Civil Engineering Practice,; pp. 519-529.
Observations on the Nature and Mechanism of the Structure of Turbulent Boundary Layers: A Survey ... more Observations on the Nature and Mechanism of the Structure of Turbulent Boundary Layers: A Survey and New Results. CR Chu, M Parlange, W Eichinger, G Katul Recent Advances in Engineering Mechanics and Their Impact on Civil Engineering Practice,, 519-529. 25 Geotechnical Engineering(CE).
ASCE, NEW YORK, NY,(USA)., 1994
The distribution of atmospheric water vapor across a step change in surface humidity (dry-wet) wa... more The distribution of atmospheric water vapor across a step change in surface humidity (dry-wet) was observed by a Lidar measurement technique under neutral atmospheric stability condition. The technique uses multiple elevation scans from a scanning water Raman-Lidar to construct a time-averaged image of the variation in water vapor concentration with height and distance. The measurements were obtained from a bare soil field in California's central valley. The growth of the vapor blanket over the wet surface was identified by the spatial ...
PROCEEDINGS OF THE CONGRESS-INTERNATIONAL ASSOCIATION FOR HYDRAULIC RESEARCH, 2001
Abstract: A finite difference predictor-corrector TVD scheme is developed for the simulation of u... more Abstract: A finite difference predictor-corrector TVD scheme is developed for the simulation of unsteady one-dimensional dam-break flows. The accuracy and robustness of the numerical scheme is verified with an analytic solution. Furthermore, a sensitivity study is carried out to investigate the efficiency and robustness of four different versions of the predictor-corrector schemes. It is found that the numerical scheme will have less computational error and higher efficiency when the direction of the predictor-corrector step ...
JWE: 日本風工学研究会誌, Oct 31, 2001
JWE: 日本風工学研究会誌, Jul 14, 2006
ABSTRACT: In this research, a mathematical model is proposed for predicting wind-induced response... more ABSTRACT: In this research, a mathematical model is proposed for predicting wind-induced response of a building with a tuned mass damper (TMD) when soil-structure interaction (SSI) is considered. It may reasonably reflect soil characteristics. Furthermore, TMDs are effective devices for reducing structural vibration. This study may help researchers to more accurately evaluate wind-induced oscillation of high-rise buildings with SSI as well as select appropriate TMDs in controlling structural response. KEYWORDS: wind-induced vibration; ...