本文選題：磁流變減振器　切入點：熱耦合仿真　出處：《湘潭大學》2016年碩士論文　論文類型：學位論文

【摘要】：隨著汽車技術智能化水平的快速提高,汽車的NVH(Noise、Vibration、Harshness)問題及舒適性日益受到人們的關注,這對汽車懸架的開發(fā)與設計提出了更高的挑戰(zhàn)。磁流變減振器以MR流體為工作介質,具有優(yōu)良的電磁可控性,能為懸架智能控制提供良好的電-機耦合接口并能改善車身振動及提高舒適性。但,在汽車高速行駛時,懸架減振器將因吸收振動能量而使工作介質出現(xiàn)較嚴重的發(fā)熱,從而導致阻尼特性的惡化。本文基于Tiguan(途觀)汽車前、后懸架的阻尼要求,設計了一款采用橫向工作間隙的活塞內流道磁流變減振器(MRD),以此為本體展開其在汽車行駛時達到熱平衡狀態(tài)下的阻尼特性研究,試圖為MRD在汽車半主動懸架上的應用提供一定的理論依據(jù)。具體工作如下:1、首先通過考慮提升MRD的阻尼力,拓寬阻尼調節(jié)區(qū)間的目標下,對減振器的本體結構進行了改進和優(yōu)化,得出了其改進后關鍵零部件的結構參數(shù);并推導了阻尼力計算的數(shù)學模型,通過對磁路分析計算了繞線圈的匝數(shù)。2、基于AMESim仿真平臺結合本文設計的減振器結構尺寸,搭建了MRD的熱效應仿真模型;通過一階白噪聲濾波系統(tǒng)模擬路面激勵,分析了汽車以不同速度在不同路面行駛時MRD缸筒內流體達到熱平衡的溫度。3、在上述工作基礎上,建立了MRD缸筒內流體的三維實體仿真模型,運用ICEM軟件對模型進行了結構化網格劃分;通過ANSYS CFX瞬態(tài)移動網格模擬活塞振動并耦合熱平衡溫度從流體的角度計算了MRD的示功曲線,結果顯示隨著車速的增加,MRD的阻尼特性有較大程度的下降。4、最后通過恒溫加熱模擬減振器的熱平衡溫度在振動試驗臺上對MRD的阻尼特性進行了測試,測試結果與仿真結論基本吻合,通過對比MRD室溫下不考慮工作熱平衡溫度的測試曲線,可知相同電流下減振器考慮熱-溫效應的阻尼力有較明顯的下降,車速越高下降越大,因此車輛在實際使用減振器時應考慮熱平衡溫度這一因素的影響。此外根據(jù)試驗曲線可以推斷,振動試驗臺自身的振動可影響示功曲線的飽滿性,測試時可相應的提高試驗臺的剛度。
[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.
【學位授予單位】：湘潭大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：U463.33
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本文編號：1607588