扩散段洞壁位置度偏差对汽车风洞流场影响的试验研究
Experimental Study on the Influence of Diffusion-Section Wall Position Deviation on the Flow Field of Automobile Wind Tunnel

开展汽车风洞扩散段洞壁位置度偏差对流场影响的试验研究，是为了确认汽车风洞工程建设过程中混凝土部段内洞壁位置度偏差对试验段流场的影响情况，并为汽车风洞建设过程中混凝土施工工艺条件把控标准提供依据。试验在某实验室气动声学风洞开展，将前后缘5？倒角的软质平板模型安装在风洞动力段下游扩散段单侧壁以模拟风洞此部段的位置度偏差。在空风洞基准状态与风洞内洞壁安装位置度偏差带两种试验工况下，分别研究了位置度偏差对速度均匀性、湍流度、气流偏角、风洞背景噪声和标模阻力测量的影响。试验结果表明：扩散段位置度偏差对试验段中央区域的速度均匀性、风洞背景噪声和气流偏角的影响较小，但对湍流度以及标模阻力测量有明显的影响。因此，汽车风洞的混凝土结构施工工艺必须严格执行行业标准以确保风洞流场品质及测试结果的可靠性。
The experimental study on the influence of the wall position deviation of the diffusion section of the automobile wind tunnel on the flow field is carried out to confirm the influence of the wall position deviation of the concrete section on the flow field of the test section in the construction process of the automobile wind tunnel, and to provide a basis for the control standard of the concrete construction process conditions in the construction process of the automobile wind tunnel. The experiment was carried out in a laboratory aeroacoustic wind tunnel. The soft flat model with a 5-degree chamfer on the front and rear edges was installed on the single side wall of the downstream diffusion section of the power section of the wind tunnel to simulate the position deviation of this section of the wind tunnel. Under the two test conditions of the empty wind tunnel reference state and the wall installation position deviation zone in the wind tunnel, the influence of the position deviation on the velocity uniformity, turbulence, flow deflection an-gle, wind tunnel background noise and mold resistance measurement was studied respectively. The test results show that the diffusion section position deviation has little influence on the velocity uniformity, wind tunnel background noise and flow deflection angle of the central area of the test section, but has a significant influence on the turbulence and the mold resistance measurement. Therefore, the construction process of the concrete structure of the automobile wind tunnel must be strictly implemented in accordance with the industry standards to ensure the quality of the wind tunnel flow field and the reliability of the test results.