Droplet turbulence effect on gas-water separator with corrugated plates is explored using the Eulerian-Lagrangian two-way coupled multiphase approach of FLUENT. It is concluded that the inertial force is dominant in s...Droplet turbulence effect on gas-water separator with corrugated plates is explored using the Eulerian-Lagrangian two-way coupled multiphase approach of FLUENT. It is concluded that the inertial force is dominant in separating large droplets, while droplet turbulence dispersion plays a decisive role in separating fine droplets. Good agreement exists between calculations and air-water experiments. The numerical method developed provides a rea-sonable description of the droplet trajectories and separating efficiency, and it can be applied to predicting the performance of gas-water separator with corrugated plates.展开更多
Debris flow can cause serious damages to roads, bridges, buildings and other infrastructures.Arranging several rows of deceleration baffles in the significant influence on the mobility and deposition characteristic of...Debris flow can cause serious damages to roads, bridges, buildings and other infrastructures.Arranging several rows of deceleration baffles in the significant influence on the mobility and deposition characteristic of debris flow. The deposit amount first increased then decreased when the flow density rises,flow path can reduce the flow velocity and ensure better protection of life and property. In debris flow prevention projects, deceleration baffles can effectively reduce the erosion of the debris flow and prolong the running time of the drainage channel.This study investigated the degree to which a 6 m long flume and three rows of deceleration baffles reduce the debris flow velocity and affect the energy dissipation characteristics. The influential variables include channel slope, debris flow density, and spacing between baffle rows. The experimental results demonstrated that the typical flow pattern was a sudden increase in flow depth and vertical proliferation when debris flow flows through the baffles. Strong turbulence between debris flow and baffles can contribute to energy dissipation and decrease the kinematic velocity considerably. The results showed that the reduction ratio of velocity increased with the increase in debris flow density,channel slope and spacing between rows. Tests phenomena also indicated that debris flow density hasand the deposit amount of debris flow density of 1500kg/m^3 reached the maximum when the experimental flume slope is 12°.展开更多
Liquid sloshing is a type of free surface flow inside a partially filled water tank.Sloshing exerts a significant effect on the safety of liquid transport systems;in particular,it may cause large hydrodynamic loads wh...Liquid sloshing is a type of free surface flow inside a partially filled water tank.Sloshing exerts a significant effect on the safety of liquid transport systems;in particular,it may cause large hydrodynamic loads when the frequency of the tank motion is close to the natural frequency of the tank.Perforated plates have recently been used to suppress the violent movement of liquids in a sloshing tank at resonant conditions.In this study,a numerical model based on OpenF OAM(Open Source Field Operation and Manipulation),an open source computed fluid dynamic code,is used to investigate resonant sloshing in a swaying tank with a submerged horizontal perforated plate.The numerical results of the free surface elevations are first verified using experimental data,and then the flow characteristics around the perforated plate and the fluid velocity distribution in the entire tank are examined using numerical examples.The results clearly show differences in sloshing motions under first-order and third-order resonant frequencies.This study provides a better understanding of the energy dissipation mechanism of a horizontal perforated plate in a swaying tank.展开更多
In this study low-concentration wastewater was investigated in the integral two-phase anaerobic baffled reactor by determining the removal of COD at various HRT,reflex ratios,and temperatures. Results indicate that th...In this study low-concentration wastewater was investigated in the integral two-phase anaerobic baffled reactor by determining the removal of COD at various HRT,reflex ratios,and temperatures. Results indicate that the removal efficiency of COD is more than 90% at 25 ℃ and 10-h HRT with no wastewater recycled,and the removal efficiency is up to 88% at 8-h HRT and reflex ratio of 150%. The removal efficiency is decreased with the decreasing temperature and HRT. The removal efficiency of COD is approximately 60% at 10 ℃,which proves that the temperature does not affect it apparently. This research has significance for reducing the cost of wastewater and sludge treatment in cold area.展开更多
This paper presents the experimental pressure loss of water flow through perforated plates with geometry similar to the ones of the bottom end piece of a Pressurized Water Reactors （PWR） fuel element. Geometric feat...This paper presents the experimental pressure loss of water flow through perforated plates with geometry similar to the ones of the bottom end piece of a Pressurized Water Reactors （PWR） fuel element. Geometric features like the number, pattern and diameter of holes were evaluated as well as different inlet chamfers. The recovering pressure profile downstream of the plates was also measured. The experimental results were compared with numerical modeling performed with the commercial Computational Fluid Dynamics （CFD） code CFX 11.0. The analysis of the results shows that the standard k-e turbulence model presents the best compromise between computing time and accuracy for the calculation of the total pressure loss through the perforated plates tested.展开更多
基金Supported by National Key Laboratory of Bubble Physics and Natural Circulation (2005)
文摘Droplet turbulence effect on gas-water separator with corrugated plates is explored using the Eulerian-Lagrangian two-way coupled multiphase approach of FLUENT. It is concluded that the inertial force is dominant in separating large droplets, while droplet turbulence dispersion plays a decisive role in separating fine droplets. Good agreement exists between calculations and air-water experiments. The numerical method developed provides a rea-sonable description of the droplet trajectories and separating efficiency, and it can be applied to predicting the performance of gas-water separator with corrugated plates.
基金supported by the National Key Technology Research and Development Program of China (No. 2014BAL05B01)the Science and Technology Service Network Initiative of Chinese Academy of Sciences (No. KFJ-EW-STS-094)+1 种基金the National Science Foundation of China (No. 41302283)the West Light Foundation of Chinese Academy of Sciences
文摘Debris flow can cause serious damages to roads, bridges, buildings and other infrastructures.Arranging several rows of deceleration baffles in the significant influence on the mobility and deposition characteristic of debris flow. The deposit amount first increased then decreased when the flow density rises,flow path can reduce the flow velocity and ensure better protection of life and property. In debris flow prevention projects, deceleration baffles can effectively reduce the erosion of the debris flow and prolong the running time of the drainage channel.This study investigated the degree to which a 6 m long flume and three rows of deceleration baffles reduce the debris flow velocity and affect the energy dissipation characteristics. The influential variables include channel slope, debris flow density, and spacing between baffle rows. The experimental results demonstrated that the typical flow pattern was a sudden increase in flow depth and vertical proliferation when debris flow flows through the baffles. Strong turbulence between debris flow and baffles can contribute to energy dissipation and decrease the kinematic velocity considerably. The results showed that the reduction ratio of velocity increased with the increase in debris flow density,channel slope and spacing between rows. Tests phenomena also indicated that debris flow density hasand the deposit amount of debris flow density of 1500kg/m^3 reached the maximum when the experimental flume slope is 12°.
基金supported by the National Natural Science Foundation of China(Nos.51490675,51322903,and 51279224)
文摘Liquid sloshing is a type of free surface flow inside a partially filled water tank.Sloshing exerts a significant effect on the safety of liquid transport systems;in particular,it may cause large hydrodynamic loads when the frequency of the tank motion is close to the natural frequency of the tank.Perforated plates have recently been used to suppress the violent movement of liquids in a sloshing tank at resonant conditions.In this study,a numerical model based on OpenF OAM(Open Source Field Operation and Manipulation),an open source computed fluid dynamic code,is used to investigate resonant sloshing in a swaying tank with a submerged horizontal perforated plate.The numerical results of the free surface elevations are first verified using experimental data,and then the flow characteristics around the perforated plate and the fluid velocity distribution in the entire tank are examined using numerical examples.The results clearly show differences in sloshing motions under first-order and third-order resonant frequencies.This study provides a better understanding of the energy dissipation mechanism of a horizontal perforated plate in a swaying tank.
基金Sponsored by the National Natural Science Foundation of China(Grant No. 50778080)China's Jilin Province Office of Education(Grant No.200696)Scientific Research Project of the Chinese Ministry of Education(Grant No.03034)
文摘In this study low-concentration wastewater was investigated in the integral two-phase anaerobic baffled reactor by determining the removal of COD at various HRT,reflex ratios,and temperatures. Results indicate that the removal efficiency of COD is more than 90% at 25 ℃ and 10-h HRT with no wastewater recycled,and the removal efficiency is up to 88% at 8-h HRT and reflex ratio of 150%. The removal efficiency is decreased with the decreasing temperature and HRT. The removal efficiency of COD is approximately 60% at 10 ℃,which proves that the temperature does not affect it apparently. This research has significance for reducing the cost of wastewater and sludge treatment in cold area.
文摘This paper presents the experimental pressure loss of water flow through perforated plates with geometry similar to the ones of the bottom end piece of a Pressurized Water Reactors （PWR） fuel element. Geometric features like the number, pattern and diameter of holes were evaluated as well as different inlet chamfers. The recovering pressure profile downstream of the plates was also measured. The experimental results were compared with numerical modeling performed with the commercial Computational Fluid Dynamics （CFD） code CFX 11.0. The analysis of the results shows that the standard k-e turbulence model presents the best compromise between computing time and accuracy for the calculation of the total pressure loss through the perforated plates tested.
