Based on numerical method, effects of silt particle with certain silt mean diameter and silt concentration on the evolution of cavitation in a centrifugal pump were studied. Silt mean diameter 0.005 mm and silt concen...Based on numerical method, effects of silt particle with certain silt mean diameter and silt concentration on the evolution of cavitation in a centrifugal pump were studied. Silt mean diameter 0.005 mm and silt concentration 1.0% were adopted in numerical simulations. Cavitation flow in a flat- nosed cylinder was simulated to validate the designed algorithm. Cavitaton flows of water and silt-laden water were simulated and compared. The results indicate that the silt particles promote the evolution of cavitation. At the outlet pressure of 6.0×10^5 Pa, cavitation bubbles do not exist in the water flow, but a few cavitation bubbles appeare in the silt-laden water flow, demonstrating the silt particles induce the formation of cavitation bubbles. At the outlet pressure of 5.29×10^5 Pa, the vapor volume fraction in the silt-laden water flow is much larger than that in the water flow, indicating that the silt particles enhance the evolution of cavitation. The properties of silt particle, static pressure, flow field structure, turbulent kinetic energy and density difference have a close relationship with the evolution of cavitation.展开更多
This paper analyzes the observing results of vacuum degree in the the Jialichen bridge-head experimental site .The cause of vacuum degree developing below groundwater table is pointed out. The influence of vacuum degr...This paper analyzes the observing results of vacuum degree in the the Jialichen bridge-head experimental site .The cause of vacuum degree developing below groundwater table is pointed out. The influence of vacuum degree above the ground water table on pore water pressure is discussed. The results show that vacuum degree decreases along the depth because resistance. The resistance in the PVDS is lowest, in the silt is highest. Vacuum degree below groundwater table is produced mainly by dewatering or by escaping of sealed air from the end of flexible pipe. Vacuum degree above the ground water table in the sand drains makes great effect on pore water pressure. In the silt the pore water pressure does not change with the variation of vacuum degree under membrane in a short time.展开更多
基金Gansu Province Natural Science Foundation of China(18JR3RA149)
文摘Based on numerical method, effects of silt particle with certain silt mean diameter and silt concentration on the evolution of cavitation in a centrifugal pump were studied. Silt mean diameter 0.005 mm and silt concentration 1.0% were adopted in numerical simulations. Cavitation flow in a flat- nosed cylinder was simulated to validate the designed algorithm. Cavitaton flows of water and silt-laden water were simulated and compared. The results indicate that the silt particles promote the evolution of cavitation. At the outlet pressure of 6.0×10^5 Pa, cavitation bubbles do not exist in the water flow, but a few cavitation bubbles appeare in the silt-laden water flow, demonstrating the silt particles induce the formation of cavitation bubbles. At the outlet pressure of 5.29×10^5 Pa, the vapor volume fraction in the silt-laden water flow is much larger than that in the water flow, indicating that the silt particles enhance the evolution of cavitation. The properties of silt particle, static pressure, flow field structure, turbulent kinetic energy and density difference have a close relationship with the evolution of cavitation.
文摘This paper analyzes the observing results of vacuum degree in the the Jialichen bridge-head experimental site .The cause of vacuum degree developing below groundwater table is pointed out. The influence of vacuum degree above the ground water table on pore water pressure is discussed. The results show that vacuum degree decreases along the depth because resistance. The resistance in the PVDS is lowest, in the silt is highest. Vacuum degree below groundwater table is produced mainly by dewatering or by escaping of sealed air from the end of flexible pipe. Vacuum degree above the ground water table in the sand drains makes great effect on pore water pressure. In the silt the pore water pressure does not change with the variation of vacuum degree under membrane in a short time.
