支撑地板对高速列车模型风洞气动噪声试验影响

Influence of supporting plate on aero-acoustic wind tunnel test for high speed train

采用数值模拟的方法从定常和非定常流动及气动噪声的角度,分析了高速列车模型在声学风洞中进行气动噪声试验时其支撑地板对测量的影响及其产生的原因,在此基础上提出了改善地板设计的方法,并对其优劣进行了评估。研究表明:支撑地板的存在使头车来流的方向发生偏转,形成鼻尖位置开始气流的上下流量分配发生变化,影响了头尾车鼻尖位置、转向架位置的流动,使其噪声特性发生变化;加长地板的措施使头车来流方向得以改善,其流动特性和气动噪声特性更接近于无支撑地板的情况,说明该措施可以改善地板对模型气动噪声试验测量的影响。

Numerical simulations of flow and aero-acoustics generated by the plate supporting high speed train model in aero-acoustic wind tunnel test are conducted to investigate the influence of the supporting plate on wind tunnel test and the causes. An optimization method of lengthening the plate is brought out based on the result of numerical simulations. Test results showed that the supporting plate caused deflection of the incoming flow, which changed air distribution taking place near the nose. This led to an impact on the unsteady flow, followed by a noise distribution change near nose and bogie. The lengthened plate reduced the deflection and made the flow and noise features much closer to the ＂without-plate＂ situation, indicating that this measure is useful for lowering the plate influence on high speed train aero-acoustic wind tunnel test.