Analysis And Optimization Of Influencing Factor Of HD-2Automotive Model Wind Tunnel Test Data

Automotive wind tunnel test is an important means of automotive aerodynamics research and the research results related to automotive aerodynamic characteristics can not be separated from the experimental verification. Therefore, it is of great importance to further research on automotive wind tunnel test, which needs to ensure the accuracy of data acquisition for the wind tunnel test. The accuracy of the data acquisition will be subject to many influencing factors, so discussing and improvement on influencing factors around the wind tunnel test data, aiming at Hunan University HD-2wind tunnel, will be undertook research in this article.The research contents are as follows:Firstly, find out the relevant factors that affect the accuracy of test data, including primarily dimension parameter of test section, wall interference, processing and installation of the model, boundary layer, flow field quality, system measuring error and other specific factors. Then analyze their impact on the test data and improve some influencing factors.Secondly, analyze and improve Hunan University wind tunnel boundary layer’s pump system. Analyze its impact on air velocity in flow field of test section, boundary layer thickness, static pressure and other aspects. And based on the original suction system, research its porosity of the plate, ratio of the plate thickness to the hole diameter and suction flow rate and other factors in the suction plate hole, which will affect the suction results. Thus get a better program about the design of suction by comparison.Thirdly, having analyzed flow field quality for Hunan University test section and we can know that some evaluation indexes meet the requirements generally, such as velocity uniformity, direction uniformity, turbulence intensity and static pressure gradient. On the basis of it, investigate the impact on flow field quality affected by honeycomb and corner flow deflectors.Fourthly, on account of the research of the impact on flow field quality in test section affected by corner flow deflectors, we optimize spatial layout parameter of corner flow deflectors with the optimizing method of approximate surrogate models. It can improve flow field quality in test section and plays an important role in improving the accuracy of test data acquisition.In the end, all the work is summarized, according to the investigation of predecessors and my own about the influencing factors of wind tunnel test data, and looked forward to the next study.