活塞内流道磁流变减振器热耦合分析及减振效果研究

发布时间：2018-03-13 18:17

  本文选题：磁流变减振器　切入点：热耦合仿真　出处：《湘潭大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着汽车技术智能化水平的快速提高,汽车的NVH(Noise、Vibration、Harshness)问题及舒适性日益受到人们的关注,这对汽车悬架的开发与设计提出了更高的挑战。磁流变减振器以MR流体为工作介质,具有优良的电磁可控性,能为悬架智能控制提供良好的电-机耦合接口并能改善车身振动及提高舒适性。但,在汽车高速行驶时,悬架减振器将因吸收振动能量而使工作介质出现较严重的发热,从而导致阻尼特性的恶化。本文基于Tiguan(途观)汽车前、后悬架的阻尼要求,设计了一款采用横向工作间隙的活塞内流道磁流变减振器(MRD),以此为本体展开其在汽车行驶时达到热平衡状态下的阻尼特性研究,试图为MRD在汽车半主动悬架上的应用提供一定的理论依据。具体工作如下:1、首先通过考虑提升MRD的阻尼力,拓宽阻尼调节区间的目标下,对减振器的本体结构进行了改进和优化,得出了其改进后关键零部件的结构参数;并推导了阻尼力计算的数学模型,通过对磁路分析计算了绕线圈的匝数。2、基于AMESim仿真平台结合本文设计的减振器结构尺寸,搭建了MRD的热效应仿真模型;通过一阶白噪声滤波系统模拟路面激励,分析了汽车以不同速度在不同路面行驶时MRD缸筒内流体达到热平衡的温度。3、在上述工作基础上,建立了MRD缸筒内流体的三维实体仿真模型,运用ICEM软件对模型进行了结构化网格划分;通过ANSYS CFX瞬态移动网格模拟活塞振动并耦合热平衡温度从流体的角度计算了MRD的示功曲线,结果显示随着车速的增加,MRD的阻尼特性有较大程度的下降。4、最后通过恒温加热模拟减振器的热平衡温度在振动试验台上对MRD的阻尼特性进行了测试,测试结果与仿真结论基本吻合,通过对比MRD室温下不考虑工作热平衡温度的测试曲线,可知相同电流下减振器考虑热-温效应的阻尼力有较明显的下降,车速越高下降越大,因此车辆在实际使用减振器时应考虑热平衡温度这一因素的影响。此外根据试验曲线可以推断,振动试验台自身的振动可影响示功曲线的饱满性,测试时可相应的提高试验台的刚度。
[Abstract]:With the rapid improvement of the intelligent level of automobile technology, people pay more and more attention to the problem and comfort of vehicle NVHN NoiseVibrationVibration.This poses a higher challenge to the development and design of automobile suspension. Mr fluid is used as the working medium for Mr damper. It has excellent electromagnetic controllability, can provide good electric-mechanical coupling interface for suspension intelligent control, and can improve body vibration and comfort. The shock absorber of suspension will cause serious heating in working medium because of absorbing vibration energy, which will lead to the deterioration of damping characteristics. This paper bases on the damping requirement of front and rear suspension of Tiguan vehicle. A magnetic rheological damper (MRD) with transverse working clearance is designed to study the damping characteristics of a piston with heat balance when it is running. This paper attempts to provide some theoretical basis for the application of MRD in automobile semi-active suspension. The specific work is as follows: 1. First of all, by considering raising the damping force of MRD, we can broaden the damping regulation range. The body structure of the damper is improved and optimized, and the structural parameters of the key parts after the improvement are obtained, and the mathematical model of the damping force calculation is derived. By analyzing the magnetic circuit, the turn number of winding coil is calculated. Based on the AMESim simulation platform, the thermal effect simulation model of MRD is built, and the road excitation is simulated by the first order white noise filter system. In this paper, the temperature of heat balance in MRD cylinder is analyzed when the vehicle is driving at different speeds on different roads. On the basis of the above work, a three-dimensional solid simulation model of the fluid in MRD cylinder is established. The model is structured meshed with ICEM software, the ANSYS CFX transient moving grid is used to simulate the piston vibration and the thermal equilibrium temperature is coupled to calculate the power curve of MRD from the point of view of fluid. The results show that the damping characteristic of MRD decreases to a large extent with the increase of speed. Finally, the damping characteristics of MRD are tested on the vibration test rig by using the constant temperature heating to simulate the thermal equilibrium temperature of the damper. The test results are in good agreement with the simulation results. By comparing the test curves with MRD at room temperature without considering the working thermal equilibrium temperature, it is known that the damping force of the damper considering the thermo-temperature effect has a more obvious decrease under the same current, and the higher the speed is, the greater the decrease is. Therefore, the influence of heat balance temperature should be taken into account in the actual use of shock absorber. In addition, it can be inferred from the test curve that the vibration of the vibration test rig itself can affect the fullness of the indicator curve. The stiffness of the test bench can be improved accordingly.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.33
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本文编号：1607588