位于剪切层的移测架流固耦合分析

Fluid structure Interaction of Traversing System in Shear Layer

摘要:

基于数值计算与风洞试验相结合，研究了移测架的流动特性，验证了采用数值方法的准确性.通过分析剪切层内的移测架的受力，得知：移测架受到的总气动阻力和总气动升力随着它与喷口距离的增加而增加，其增加速度在距离为5 m时达到最大.利用流固耦合计算方法，了解到移测架受到的最大气动升力远大于平均气动升力，约在3倍左右.升阻力不再具有单一频率特性，而是在2~60 Hz内分布着较大的振幅.如此宽范围的频率容易引起移测架共振，从而使移测架发生强烈抖动，导致测点定位的不准确，影响到汽车风洞试验数据的准确度.

Abstract:

Based on a combination of numerical simulation and wind tunnel, flow behavior of the traversing system was investigated and the feasibility of numerical method was proved. The aerodynamic forces acting on the traversing system under different situations were calculated. It is found that with the increasing of the distance between the traversing system and the nozzle, the force increases, and the growth rate peaks at a distance of 5 m. Based on the method of fluid structure interaction, it is found that the maximum unsteady lift force is larger than the average forces, which is about 3 times. The single frequency characteristic isn’t found at the power spectral density of drag and lift forces. High amplitude occurs at the frequency from 2 to 60 Hz, which is easy to lead to resonate the traversing system. It must cause a severe vibration of the system, which results in the inaccuracy of the automotive wind tunnel test data.