利用汽车行驶风测试结构气动力系数的车振影响分析?

参照结构风洞试验和现场实测的方法，结合车辆行驶能产生风的特点，提出一种理想道路条件下利用汽车行驶风测试结构气动力系数的跑车试验方法，该方法可成为风洞试验的有益补充。然而，汽车在行驶中由于路面不平整、发动机抖动及机械传动等因素作用下不可避免地产生振动，搭载于车上的结构模型由于该车辆振动的影响将受到惯性力的作用，该惯性力也会被测力天平采集，造成结果失真。采用理论推导和现场试验的方法，构建了跑车试验的基本理论，设计和组装了跑车试验的物理试验平台，运用该方法对参考文献三棱柱模型的升、阻力系数进行测试，同时对汽车行驶振动的影响进行研究。结果表明：在理想道路条件下，跑车试验理论公式正确，构建的跑车试验装置合理，等腰三棱柱模型的升、阻力系数跑车试验测试结果与风洞试验结果吻合很好，汽车行驶振动对利用汽车行驶风测试三棱柱模型升、阻力系数的影响很小，可忽略不计。跑车试验为结构抗风研究提供了一种新的试验方法。

Analysis of Vehicle Vibration Impact on Measuring Aerodynamic Coefficients of Structures Using the Wind Generated by a Moving Vehicle

Referring to the methods of wind tunnel experiment and field measurement on aerodynamic coefficients of structures, and combining the characteristic of a moving vehicle can produce wind, a kind of test method for measuring aerodynamic coefficients of structures is presented. This method can be a useful supplement to wind tunnel test. However, when the vehicle is running, the vibration is inevitable because of the pavement unevenness and engine vibration. The test model on the vehicle will be affected by the inertial force due to the vibration, and the inertia force will be collected by dynamometer, resulting in distortion of the results. On the basis of theoretical derivation and field test, the basic theory of transiting test was constructed. The physical test platform of transiting test was designed and assembled. The method of test data processing was studied. The transiting test method was used to measure the lift and drag coefficient of a triangular prism model in the quoted references. At the same time, the influence of vehicle vibration is studied. The results show that: under the ideal road condition, the theoretical formula of the transiting test presented in this paper is correct. The system of hardware and software is reasonable. The test results of lift and drag coefficients of the triangular prism model show good agreement with the wind tunnel test results of the relevant literatures. The impact of vehicle vibration on the aerodynamic coefficients of a vehicle is very small, and it can be neglected completely. The feasibility of this method under ideal road condition is verified. The study on transiting test provides a new test method for structural wind resistance.