Water jets are widely used in seabed scouring and desilting applications.In the present work,dedicated tests have been conducted using a jet scour model test platform and sand beds containing grains with different siz...Water jets are widely used in seabed scouring and desilting applications.In the present work,dedicated tests have been conducted using a jet scour model test platform and sand beds containing grains with different sizes.The FLOW-3D simulation software has also been used to tackle the problem form a numerical point of view.The boundary conditions of the simulation have been optimized to reduce the gap between the numerical results and the outcomes of the experimental tests.Scour area calculation has been based on a RNG k-εTurbulence model.Moreover,the FAVOR(Fractional Area Volume Obstacle Representation)technology has been selected for grid division to make the simulation results more accurate.Jet scours with inclination angles of 10–20°have been simulated.It has been found that jet scouring is greatly affected by the environmental water flow,that is,water flow can weaken the scouring capacity of the jets.展开更多
From the perspective of COVID-19’s prevention and control, to test effectiveness of existing control measures for shopping center buildings, taking Weilaishi Shopping Center of Handan City as an example, Anylogic sof...From the perspective of COVID-19’s prevention and control, to test effectiveness of existing control measures for shopping center buildings, taking Weilaishi Shopping Center of Handan City as an example, Anylogic software is used for analogue simulation of the whole shopping process. According to existing control means of Weilaishi Shopping Center, the model sets three different simulation conditions: “no control state”, “restricting entrance and exit opening” and “increasing epidemic prevention distance”. The epidemic prevention effects of different control methods are intuitively displayed through the simulated output thermal diagram and the statistical diagram of the number of infected people. The results show that restricting the opening of entrances and exits can reduce the number of infected people by 36%, and increasing the epidemic prevention distance can reduce the number of infected people by 89.8%. Both control methods can play a certain epidemic prevention effect.展开更多
Due to the risk of thermal runaway in the charging and discharging process of a soft packed lithium battery pack for electric vehicles,a stamping channel liquid cooling plate cooling system is designed,and then the he...Due to the risk of thermal runaway in the charging and discharging process of a soft packed lithium battery pack for electric vehicles,a stamping channel liquid cooling plate cooling system is designed,and then the heat dissipation problem of the battery pack is solved through reasonable thermal management control strategy.Using computational fluid dynamics simulation software star-CCM+,the thermal management control strategy is optimized through simulation technology,and the temperature field distribution of battery pack is obtained.Finally,an experimental platform is built,combined with experiments,the effectiveness of the thermal management control strategy of the cooling system is verified.The results show that when the battery pack is in the environment of 25℃,the maximum temperature of the cooling system can be lower than 40℃,the maximum temperature difference between all single batteries is within 5℃,and the maximum temperature difference between inlet and outlet coolant is 3℃,which can meet the heat dissipation requirements of the battery pack and prevent out of control heat generation.展开更多
基金This work is supported by National Nature Fund of China(52071091)the Key Laboratory of Expressway Construction Machinery of Shanxi Province which is gained by Zhang(300102259512).
文摘Water jets are widely used in seabed scouring and desilting applications.In the present work,dedicated tests have been conducted using a jet scour model test platform and sand beds containing grains with different sizes.The FLOW-3D simulation software has also been used to tackle the problem form a numerical point of view.The boundary conditions of the simulation have been optimized to reduce the gap between the numerical results and the outcomes of the experimental tests.Scour area calculation has been based on a RNG k-εTurbulence model.Moreover,the FAVOR(Fractional Area Volume Obstacle Representation)technology has been selected for grid division to make the simulation results more accurate.Jet scours with inclination angles of 10–20°have been simulated.It has been found that jet scouring is greatly affected by the environmental water flow,that is,water flow can weaken the scouring capacity of the jets.
基金Sponsored by Hebei Social Science Development Research Project in 2021 (20210301135)。
文摘From the perspective of COVID-19’s prevention and control, to test effectiveness of existing control measures for shopping center buildings, taking Weilaishi Shopping Center of Handan City as an example, Anylogic software is used for analogue simulation of the whole shopping process. According to existing control means of Weilaishi Shopping Center, the model sets three different simulation conditions: “no control state”, “restricting entrance and exit opening” and “increasing epidemic prevention distance”. The epidemic prevention effects of different control methods are intuitively displayed through the simulated output thermal diagram and the statistical diagram of the number of infected people. The results show that restricting the opening of entrances and exits can reduce the number of infected people by 36%, and increasing the epidemic prevention distance can reduce the number of infected people by 89.8%. Both control methods can play a certain epidemic prevention effect.
文摘Due to the risk of thermal runaway in the charging and discharging process of a soft packed lithium battery pack for electric vehicles,a stamping channel liquid cooling plate cooling system is designed,and then the heat dissipation problem of the battery pack is solved through reasonable thermal management control strategy.Using computational fluid dynamics simulation software star-CCM+,the thermal management control strategy is optimized through simulation technology,and the temperature field distribution of battery pack is obtained.Finally,an experimental platform is built,combined with experiments,the effectiveness of the thermal management control strategy of the cooling system is verified.The results show that when the battery pack is in the environment of 25℃,the maximum temperature of the cooling system can be lower than 40℃,the maximum temperature difference between all single batteries is within 5℃,and the maximum temperature difference between inlet and outlet coolant is 3℃,which can meet the heat dissipation requirements of the battery pack and prevent out of control heat generation.
