基于熵产理论并结合响应面法,对V+U组合形节流槽滑阀的结构参数进行优化设计,旨在降低液压系统中的能量损失、提升流量控制性能。通过数值模拟分析了不同开度下的熵产分布、速度场与压力场特性,确定以40%开度作为典型工况,采用Plackett-...基于熵产理论并结合响应面法,对V+U组合形节流槽滑阀的结构参数进行优化设计,旨在降低液压系统中的能量损失、提升流量控制性能。通过数值模拟分析了不同开度下的熵产分布、速度场与压力场特性,确定以40%开度作为典型工况,采用Plackett-Burma试验筛选出对总熵产影响显著的三个关键影响因素:U形槽长度、V形槽深度和V形槽长度;结合最陡爬坡试验和响应面试验建立了三个影响因素与总熵产和流量增益的回归方程,对影响因素的交互作用进行分析,获得V+U形组合节流槽最优结构参数组合。结果表明:当U形槽长2.417 mm, V形槽长1.899 mm, V形槽深0.916 mm时,总熵产由优化前4590.39 mW/K降至793 mW/K,同时流量增益保持在合理范围内,模型预测误差小于5%。所得结论可为V+U形组合节流槽能量损失研究提供理论参考。展开更多
This paper presents an analytical investigation of water hammer in a hydraulic pressurized pipe system with a throttled surge chamber located at the junction between a tunnel and a penstock, and a valve positioned at ...This paper presents an analytical investigation of water hammer in a hydraulic pressurized pipe system with a throttled surge chamber located at the junction between a tunnel and a penstock, and a valve positioned at the downstream end of the penstock. Analytical formulas of maximum water hammer pressures at the downstream end of the tunnel and the valve were derived for a system subjected to linear and slow valve closure. The analytical results were then compared with numerical ones obtained using the method of characteristics. There is agreement between them. The formulas can be applied to estimating water hammer pressure at the valve and transmission of water hammer pressure through the surge chamber at the junction for a hydraulic pipe system with a surge chamber.展开更多
Based on the solution of the governing differential equation for deformation of throttle slice while satisfying required boundary conditions, the coefficient （Gr） and an analytical formula for computing the deformat...Based on the solution of the governing differential equation for deformation of throttle slice while satisfying required boundary conditions, the coefficient （Gr） and an analytical formula for computing the deformation of throttle slice is presented through equivalency transformation, which is a concise, accurate and practical method for throttle slice design and characteristic analysis. Researched the deformation at any radius, compared with ANSYS FEA software by the simulation analysis, the availability opening size of throttle that was defined by the deformation at the valve mouth radius is studied. The affection of valve mouth radius to the damper characteristic is analyzed. Tests are made for the damper characteristic, compared with simulation results, it is shown that Gr method is an accurate computation method for computing the deformation of throttle slice at valve mouth radius, suitihle to use in the damper design, analysis, and verification. The deformation at mouth radius could not be replaced with the outside radius.展开更多
文摘基于熵产理论并结合响应面法,对V+U组合形节流槽滑阀的结构参数进行优化设计,旨在降低液压系统中的能量损失、提升流量控制性能。通过数值模拟分析了不同开度下的熵产分布、速度场与压力场特性,确定以40%开度作为典型工况,采用Plackett-Burma试验筛选出对总熵产影响显著的三个关键影响因素:U形槽长度、V形槽深度和V形槽长度;结合最陡爬坡试验和响应面试验建立了三个影响因素与总熵产和流量增益的回归方程,对影响因素的交互作用进行分析,获得V+U形组合节流槽最优结构参数组合。结果表明:当U形槽长2.417 mm, V形槽长1.899 mm, V形槽深0.916 mm时,总熵产由优化前4590.39 mW/K降至793 mW/K,同时流量增益保持在合理范围内,模型预测误差小于5%。所得结论可为V+U形组合节流槽能量损失研究提供理论参考。
基金supported by the National Natural Science Foundation of China (Grant No.50539070)the Major State Basic Research Development Program of China (Grant No.2006CB403304)
文摘This paper presents an analytical investigation of water hammer in a hydraulic pressurized pipe system with a throttled surge chamber located at the junction between a tunnel and a penstock, and a valve positioned at the downstream end of the penstock. Analytical formulas of maximum water hammer pressures at the downstream end of the tunnel and the valve were derived for a system subjected to linear and slow valve closure. The analytical results were then compared with numerical ones obtained using the method of characteristics. There is agreement between them. The formulas can be applied to estimating water hammer pressure at the valve and transmission of water hammer pressure through the surge chamber at the junction for a hydraulic pipe system with a surge chamber.
基金the Ministerial Level Foundation (5040001) the Nationality Excellence Doctor Thesis Foster & Encouragement Foundation of School of MechanicalVehicular Engineering,Beijing Institute of Technology(No 010003)
文摘Based on the solution of the governing differential equation for deformation of throttle slice while satisfying required boundary conditions, the coefficient （Gr） and an analytical formula for computing the deformation of throttle slice is presented through equivalency transformation, which is a concise, accurate and practical method for throttle slice design and characteristic analysis. Researched the deformation at any radius, compared with ANSYS FEA software by the simulation analysis, the availability opening size of throttle that was defined by the deformation at the valve mouth radius is studied. The affection of valve mouth radius to the damper characteristic is analyzed. Tests are made for the damper characteristic, compared with simulation results, it is shown that Gr method is an accurate computation method for computing the deformation of throttle slice at valve mouth radius, suitihle to use in the damper design, analysis, and verification. The deformation at mouth radius could not be replaced with the outside radius.
