含气油液有效体积弹性模量理论模型研究
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摘要
为准确预测含气油液在空气分离压下有效体积弹性模量的值,基于油液体积弹性模量定义和质量守恒定律,依据含气油液中气相成分随压力的变化过程,推导出含气油液有效体积弹性模量理论模型。数值计算结果表明:含气油液有效体积弹性模量理论模型B-p曲线与现有理论模型及实验数据拟合曲线基本吻合,验证了理论模型的正确性,特别是在低于大气压的极低压区,有效体积弹性模量预测值更加接近实际情况。分析了初始含气量、压力、升压时间对有效体积弹性模量的影响,结果表明:在低于空气分离压范围内,初始含气量增大,有效体积弹性模量减小;在一定范围内,升压时间增大,有效体积弹性模量小幅度增大。
In order to predict the effective bulk modulus of air-liquid mixtures of hydraulic oil below the saturation pressure accurately,based on the definition of the bulk modulus and law of mass conservation,according to the air release and cavitation processes,a theoretical model for effective bulk modulus of air-liquid mixtures of hydraulic oil below the saturation pressure was proposed.The numerical calculation results show that the B-pcurve of the theoretical model for effective bulk modulus of air-liquid mixtures of hydraulic oil shows good agreement with the B-p curves of published literature's theoretical model and fitted experimental data,verifing the accuracy of the theoretical model,especially the extreme low pressure region below the atmospheric pressure.The effective bulk modulus of air-liquid mixtures of hydraulic oil is more consistent to practical conditions.Furthermore,the effects of initial air content,pressure and pressure rising time on effective bulk modulus were analyzed.The results show that below the saturation pressure area,the effective bulk modulus deceases with the increasing of initial air content,and the effective bulk modulus increases in a narrow range with the increasing of the pressure rising time.
In order to predict the effective bulk modulus of air-liquid mixtures of hydraulic oil below the saturation pressure accurately,based on the definition of the bulk modulus and law of mass conservation,according to the air release and cavitation processes,a theoretical model for effective bulk modulus of air-liquid mixtures of hydraulic oil below the saturation pressure was proposed.The numerical calculation results show that the B-pcurve of the theoretical model for effective bulk modulus of air-liquid mixtures of hydraulic oil shows good agreement with the B-p curves of published literature's theoretical model and fitted experimental data,verifing the accuracy of the theoretical model,especially the extreme low pressure region below the atmospheric pressure.The effective bulk modulus of air-liquid mixtures of hydraulic oil is more consistent to practical conditions.Furthermore,the effects of initial air content,pressure and pressure rising time on effective bulk modulus were analyzed.The results show that below the saturation pressure area,the effective bulk modulus deceases with the increasing of initial air content,and the effective bulk modulus increases in a narrow range with the increasing of the pressure rising time.
引文
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[11]ZHOU J,VACCA A,MANHARTSGRUBER B.A Novel Approach for the Prediction of Dynamic Features of Air Release and Absorption in Hydraulic Oils[J].Journal of Fluids Engineering,2013,135(9):1790-1791.
[12]毕明树,冯殿义.工程热力学[M].北京:化学工业出版社,2001:92-101.BI Mingshu,FENG Dianyi.Engineering Thermodynamics[M].Beijing:Chemical Industry Press,2001:92-101.
[2]GHOLIZADEH H,BURTON R,SCHOENAU G.Fluid Bulk Modulus:A Literature Survey[J].International Journal of Fluid Power,2011,12(3):5-15.
[3]GHOLIZADEH H,BURTON R,SCHOENAU G.Fluid Bulk Modulus:Comparison of Low Pressure Models[J].International Journal of Fluid Power,2012,13(1):7-16.
[4]KIM S,MURRENHOFF H.Measurement of Effective Bulk Modulus for Hydraulic Oil at Low Pressure[J].Journal of Fluids Engineering,2012,134(2):130-130.
[5]YANG H,FENG B,GONG G.Measurement of Effective Fluid Bulk Modulus in Hydraulic System[J].Journal of Dynamic Systems Measurement&Control,2011,133(6):2417-2424.
[6]JIAN R,BURTON R.Bulk Modulus of Air Content Oil in a Hydraulic Cylinder[C]//ASME 2006International Mechanical Engineering Congress and Exposition.Chicago,2006:259-269.
[7]时培成,王幼民,王立涛.液压油液数字建模与仿真[J].农业机械学报,2007,38(12):148-151.SHI Peicheng,WANG Youmin,WANG Litao,Study on Modeling and Simulation of the Hydraulic Fluid[J].Transactions of the Chinese Society for Agricultural Machinery,2007,38(12):148-151.
[8]王静,龚国芳,杨华勇.油液体积模量的研究与在线测量[J].机械工程学报,2009,45(7):120-125.WANG Jing,GONG Guofang,YANG Huayong.Research and Online Measurement of Bulk Modulus of Hydraulic Oil[J].Journal of Mechanical Engineering,2009,45(7):120-125.
[9]冯斌,龚国芳,杨华勇.液压油弹性模量提高方法与试验[J].农业机械学报,2010,41(3):219-222.FENG Bin,GONG Guofang,YANG Huayong.Method and Experiment for Increasing Effective Fluid Bulk Modulus in Hydraulic Systems[J].Transactions of the Chinese Society for Agricultural Machinery,2010,41(3):219-222.
[10]杨树军,焦晓娟,鲍永,等.油液含气量对液压机械换段性能的影响[J].机械工程学报,2015,51(14):122-130.YANG Shujun,JIAO Xiaojuan,BAO Yong,et al.Fluid Air Content Affecting the Power Shift Performance of the Hydro-mechanical Variable Transmission[J].Journal of Mechanical Engineering,2015,51(14):122-130.
[11]ZHOU J,VACCA A,MANHARTSGRUBER B.A Novel Approach for the Prediction of Dynamic Features of Air Release and Absorption in Hydraulic Oils[J].Journal of Fluids Engineering,2013,135(9):1790-1791.
[12]毕明树,冯殿义.工程热力学[M].北京:化学工业出版社,2001:92-101.BI Mingshu,FENG Dianyi.Engineering Thermodynamics[M].Beijing:Chemical Industry Press,2001:92-101.