节流阀油流温升及阀芯变形研究
摘要
节流阀是电液伺服系统的重要部件。当入流口和出流口的压差较大时,通过阀口的油流速度非常大。常见的机械油粘度也较大,因此油液的粘性加热显著。这会导致阀芯膨胀,使阀被卡死而失效。针对这一现象,本文选择了工程应用中典型的节流阀,采用了CFD方法模拟了阀内的油流温升现象,分析了U形节流阀槽口结构参数、进出口压差及槽口类型对油流温升的影响。然后基于CFD模拟得到的温度场,采用FEA方法,对U形节流阀阀芯变形进行了模拟。
通过对数值模拟结果的分析,发现:U形节流阀的槽口深度越大,其最高温度随质量流量变化的速率越小;U形节流阀的最高温度随进出口压差的增大而增大,并基本成线形关系;节流阀的油液从槽口流出后形成射流,U形节流阀的射流出射角随着阀口开度的增大而减小,而V形节流阀的射流出射角保持不变;U形节流阀阀芯的局部高温分布在槽口轮廓线附近,而V形槽口节流阀的局部高温集中地出现在槽口底面上。
研究阀芯变形时,发现槽口半径小的U形槽,其阀芯最大的径向变形容易发生在槽口两侧的壁面。这种情况下,阀芯最大径向变形随着质量流量增大的速度逐渐减小。槽口深度大的U形槽,其阀芯最大的径向变形容易发生在槽口半圆壁面。
本文发现的有关节流阀油流温升及阀芯变形的规律,为改善节流阀的槽口温度分布,防止被卡死,提供了新的设计思路。本文首次采用的CFD和FEA结合的方法,也为相关领域的研究提供了参考。
The thesis presents a numerical analysis of the viscous heating and spool deformation of throttle valves. The CFD method is used to simulate the temperature distribution around the notch of the throttle valve, due to the viscous heating effect caused by high speed flow of large-viscosity hydraulic oil. Basing on the CFD result, the FEA method is used to simulate the spool deformation of the throttle valve due to the high local temperature, which is supposed to be the causation of the jam fault.
Temperature distributions of U-shape and V-shape throttle valves are simulated. The influence of three factors on the temperature distributions are investigated, including the U-shape notch structure parameters, the pressure drop and the notch type. Several conclusions are obtained: with the depth of the U-shape notch increasing, the increasing rate of the maximum temperature to the fluxes is decreased; and there is a linear relation between the maximum temperature and the inlet-outlet pressure drop; the high local temperature of U-shape throttle valve appears near the contour lines of the notch, while that of V-shape throttle valve occurs on the bottom face of the notch.
In order to study the spool deformation, the heat transfer and thermal stress on the spool of U-shape throttle valve are simulated. It is observed that the peak radial deformation of the U-shape notch spools of small radii are occurred in both side walls of the notch, and that of big depth are occurred in the semicircle wall. In the former situation, the increasing rate of the maximum radial spool deformation to the fluxes is decresed.
The thesis provides a deep insight into the jam fault problems. These conclusions presented above are important for improving the design of throttle valves to get rid of the jam fault. The experience of application of the coupling CFD and FEA provides a reference for the research of the heat transfer and deformation.
通过对数值模拟结果的分析,发现:U形节流阀的槽口深度越大,其最高温度随质量流量变化的速率越小;U形节流阀的最高温度随进出口压差的增大而增大,并基本成线形关系;节流阀的油液从槽口流出后形成射流,U形节流阀的射流出射角随着阀口开度的增大而减小,而V形节流阀的射流出射角保持不变;U形节流阀阀芯的局部高温分布在槽口轮廓线附近,而V形槽口节流阀的局部高温集中地出现在槽口底面上。
研究阀芯变形时,发现槽口半径小的U形槽,其阀芯最大的径向变形容易发生在槽口两侧的壁面。这种情况下,阀芯最大径向变形随着质量流量增大的速度逐渐减小。槽口深度大的U形槽,其阀芯最大的径向变形容易发生在槽口半圆壁面。
本文发现的有关节流阀油流温升及阀芯变形的规律,为改善节流阀的槽口温度分布,防止被卡死,提供了新的设计思路。本文首次采用的CFD和FEA结合的方法,也为相关领域的研究提供了参考。
The thesis presents a numerical analysis of the viscous heating and spool deformation of throttle valves. The CFD method is used to simulate the temperature distribution around the notch of the throttle valve, due to the viscous heating effect caused by high speed flow of large-viscosity hydraulic oil. Basing on the CFD result, the FEA method is used to simulate the spool deformation of the throttle valve due to the high local temperature, which is supposed to be the causation of the jam fault.
Temperature distributions of U-shape and V-shape throttle valves are simulated. The influence of three factors on the temperature distributions are investigated, including the U-shape notch structure parameters, the pressure drop and the notch type. Several conclusions are obtained: with the depth of the U-shape notch increasing, the increasing rate of the maximum temperature to the fluxes is decreased; and there is a linear relation between the maximum temperature and the inlet-outlet pressure drop; the high local temperature of U-shape throttle valve appears near the contour lines of the notch, while that of V-shape throttle valve occurs on the bottom face of the notch.
In order to study the spool deformation, the heat transfer and thermal stress on the spool of U-shape throttle valve are simulated. It is observed that the peak radial deformation of the U-shape notch spools of small radii are occurred in both side walls of the notch, and that of big depth are occurred in the semicircle wall. In the former situation, the increasing rate of the maximum radial spool deformation to the fluxes is decresed.
The thesis provides a deep insight into the jam fault problems. These conclusions presented above are important for improving the design of throttle valves to get rid of the jam fault. The experience of application of the coupling CFD and FEA provides a reference for the research of the heat transfer and deformation.
引文
[1]高殿荣 王益群 液压锥阀流场的有限元法解析 机床与液压 2000(2)12-14
[2]袁新明 毛根海 张土乔 阀门流道流场的数值模拟及阻力特性研究 水利发电学报 199967(4)60-66
[3]Tetsuhiro Wsukiji Yoshihiko Yonezawa Masahiko Soshino Unsteady jet flow issuing from a spool valve for repeated valve opening and closing FED-Vol 149 Separated Flows ASME 1993 189-197
[4]王林翔 陈鹰 路甬祥 液压阀道中的三维流体流动的数值分析 中国机械工程 199910(2):127-129
[5]Xiaoping Liu Hirotsugu Kasuya Yuusaku etc Flow analysis of hydraulic valve used in construction machinery(In Japanese)Proceedings of JSME Ibaraki District Conference 2001
[6]田奇 直喷式柱型液压阀流体稳态力的研究 中国机械工程 2002 13(13)1102-1104
[7]罗亚敏 刘晓红 于兰英 石复元 液压比例阀阀芯V形槽口的CFD解析 流体传动与控制 2007(5)17-23
[8]高红 傅新 杨华勇 築地徹浩 球阀阀口气穴流场的模拟与可视化研究 农业机械学报2003(3)45-48
[9]刘晓红 柯坚 于兰英 王国志液压滑阀径向间隙内温度分布的研究 机床与液压2006(11)107-109
[10]Giuseppe Del Vescovo and Antonio Lippolis Three-dimensional analysis of flow forces on directional control valves International Journal of Fluid Power 2003(2):15-24
[11]Giuseppe Del Vescovo and Antonio Lippolis A review analysis of unsteady forces in hydraulic valves International Journal of Fluid Power 2006(3):29-39
[12]高殿荣 王益群 申功 液压控制锥阀内流场的数值模拟与试验可视化研究 机械工程学报 2002(4):66-70
[13]王林翔 陈鹰 章明川 阀腔内速度场的PIV测量 机床与液压 2000(5):32-33
[14]彭楠 熊联友 陆文海 刘立强 汤建成 张亮 低温节流阀的设计与计算 低温工程2006(5)32-56
[15]冀宏 液压阀芯节流槽气穴噪声特性的研究[浙江大学博士学位论文]杭州 浙江大学2005
[16]冀宏 傅新 杨华勇 王庆丰 非全周开口滑阀压力分布测量研究 机械工程学报 2004(4):99-102
[17]冀宏 傅新 杨华勇 几种典型液压阀口过流面积分析及计算 机床与液压 2003(5)15-16
[18]冀宏 傅新 杨华勇 王庆丰 节流槽型阀口噪声特性试验研究 机械工程学报 2004(11)42-46
[19]傅新 杜学文 邹俊 杨华勇 孔隙高速流动中的气穴观测与噪声特性 机械工程学报2007(4)98-102
[20]Lugowsky J Experimental Investigation on the origin of flow forces in hydraulic piston valves 10th International conference on fluid power BHR Brugges Belgium 1993
[21]Massimo Borghi Massimo Milani Roberto Paoluzzi Influence of notch shape and number of notches on the metering characteristics of hydraulic spool valves International Journal of Fluid Power 2005(6):5-18
[22]王福军 计算流体动力学分析 北京:清华大学出版社 2004
[23]周雪漪 计算水力学 北京:清华大学出版社 1995
[24]郭鸿志 传输过程数值模拟 北京:冶金工业出版社 1998
[25]陶文铨 数值传热学(第二版)西安:西安交通大学出版社 2001
[26]付德熏 马廷文 计算流体力学 北京:高等教育出版社 2002
[27]朱自强 应用计算流体力学 北京:北京航空航天学院出版社 1998
[28]何永森 刘邵英 机械管内流体数值模拟 北京:国防工业出版社 1999
[29]Chapman D R Trends and pacing items in computational aerodynamics AIAA 79-129
[30]Moin P Kim J The structure of the vorticity field in turbulent channel flow:Part 1 Analysis of instantaneous fields statistical correlations J Fluid Mech 1985 155:441-465
[31]Kim J Moin P The structure of the vorticity field in turbulent channel flow:Part 2 Study of ensemble-averaged fields J Fluid Mech 1986 162:339-363
[32]John D Anderson JR 计算流体力学入门 北京:清华大学出版社 2002
[33]吴望一 流体力学(上册)北京:北京大学出版社 2005
[34]章梓雄 董曾南 粘性流体力学 北京:清华大学出版社 1998
[35]林建忠 湍动力学 杭州:浙江大学出版社 2000
[36]David C Wilcox Turbulence Modeling for CFD Dcw Industries 1998:21-25
[37]Launder B E and Spalding D B Mathematical models of turbulence Academic Press London England 1972
[38]Chen Y S Viscous flow computations using a second order upwind differencing scheme AIAA Paper:88-0417 AIAA 26th Aerospace Science Meeting January 1988 A
[39]Patankar V S Numerical heat transfer and fluid flow Washington:Hemisphere Publishing Corp;1980
[40]Fluent Inc Fluent6.3 user's guide 2006
[41]赵腾伦 ABAQUS6.6在机械工程中的应用 北京:中国水利水电出版社 2007
[42]石亦平 周玉蓉 ABAQUS有限元分析实例详解 北京:机械工业出版社 2006
[2]袁新明 毛根海 张土乔 阀门流道流场的数值模拟及阻力特性研究 水利发电学报 199967(4)60-66
[3]Tetsuhiro Wsukiji Yoshihiko Yonezawa Masahiko Soshino Unsteady jet flow issuing from a spool valve for repeated valve opening and closing FED-Vol 149 Separated Flows ASME 1993 189-197
[4]王林翔 陈鹰 路甬祥 液压阀道中的三维流体流动的数值分析 中国机械工程 199910(2):127-129
[5]Xiaoping Liu Hirotsugu Kasuya Yuusaku etc Flow analysis of hydraulic valve used in construction machinery(In Japanese)Proceedings of JSME Ibaraki District Conference 2001
[6]田奇 直喷式柱型液压阀流体稳态力的研究 中国机械工程 2002 13(13)1102-1104
[7]罗亚敏 刘晓红 于兰英 石复元 液压比例阀阀芯V形槽口的CFD解析 流体传动与控制 2007(5)17-23
[8]高红 傅新 杨华勇 築地徹浩 球阀阀口气穴流场的模拟与可视化研究 农业机械学报2003(3)45-48
[9]刘晓红 柯坚 于兰英 王国志液压滑阀径向间隙内温度分布的研究 机床与液压2006(11)107-109
[10]Giuseppe Del Vescovo and Antonio Lippolis Three-dimensional analysis of flow forces on directional control valves International Journal of Fluid Power 2003(2):15-24
[11]Giuseppe Del Vescovo and Antonio Lippolis A review analysis of unsteady forces in hydraulic valves International Journal of Fluid Power 2006(3):29-39
[12]高殿荣 王益群 申功 液压控制锥阀内流场的数值模拟与试验可视化研究 机械工程学报 2002(4):66-70
[13]王林翔 陈鹰 章明川 阀腔内速度场的PIV测量 机床与液压 2000(5):32-33
[14]彭楠 熊联友 陆文海 刘立强 汤建成 张亮 低温节流阀的设计与计算 低温工程2006(5)32-56
[15]冀宏 液压阀芯节流槽气穴噪声特性的研究[浙江大学博士学位论文]杭州 浙江大学2005
[16]冀宏 傅新 杨华勇 王庆丰 非全周开口滑阀压力分布测量研究 机械工程学报 2004(4):99-102
[17]冀宏 傅新 杨华勇 几种典型液压阀口过流面积分析及计算 机床与液压 2003(5)15-16
[18]冀宏 傅新 杨华勇 王庆丰 节流槽型阀口噪声特性试验研究 机械工程学报 2004(11)42-46
[19]傅新 杜学文 邹俊 杨华勇 孔隙高速流动中的气穴观测与噪声特性 机械工程学报2007(4)98-102
[20]Lugowsky J Experimental Investigation on the origin of flow forces in hydraulic piston valves 10th International conference on fluid power BHR Brugges Belgium 1993
[21]Massimo Borghi Massimo Milani Roberto Paoluzzi Influence of notch shape and number of notches on the metering characteristics of hydraulic spool valves International Journal of Fluid Power 2005(6):5-18
[22]王福军 计算流体动力学分析 北京:清华大学出版社 2004
[23]周雪漪 计算水力学 北京:清华大学出版社 1995
[24]郭鸿志 传输过程数值模拟 北京:冶金工业出版社 1998
[25]陶文铨 数值传热学(第二版)西安:西安交通大学出版社 2001
[26]付德熏 马廷文 计算流体力学 北京:高等教育出版社 2002
[27]朱自强 应用计算流体力学 北京:北京航空航天学院出版社 1998
[28]何永森 刘邵英 机械管内流体数值模拟 北京:国防工业出版社 1999
[29]Chapman D R Trends and pacing items in computational aerodynamics AIAA 79-129
[30]Moin P Kim J The structure of the vorticity field in turbulent channel flow:Part 1 Analysis of instantaneous fields statistical correlations J Fluid Mech 1985 155:441-465
[31]Kim J Moin P The structure of the vorticity field in turbulent channel flow:Part 2 Study of ensemble-averaged fields J Fluid Mech 1986 162:339-363
[32]John D Anderson JR 计算流体力学入门 北京:清华大学出版社 2002
[33]吴望一 流体力学(上册)北京:北京大学出版社 2005
[34]章梓雄 董曾南 粘性流体力学 北京:清华大学出版社 1998
[35]林建忠 湍动力学 杭州:浙江大学出版社 2000
[36]David C Wilcox Turbulence Modeling for CFD Dcw Industries 1998:21-25
[37]Launder B E and Spalding D B Mathematical models of turbulence Academic Press London England 1972
[38]Chen Y S Viscous flow computations using a second order upwind differencing scheme AIAA Paper:88-0417 AIAA 26th Aerospace Science Meeting January 1988 A
[39]Patankar V S Numerical heat transfer and fluid flow Washington:Hemisphere Publishing Corp;1980
[40]Fluent Inc Fluent6.3 user's guide 2006
[41]赵腾伦 ABAQUS6.6在机械工程中的应用 北京:中国水利水电出版社 2007
[42]石亦平 周玉蓉 ABAQUS有限元分析实例详解 北京:机械工业出版社 2006