收集口形状和角度对汽车风洞试验段轴向静压因数的影响

为研究风洞收集口形状和角度对试验段轴向静压因数的影响,通过数值仿真和试验验证研究翼型收集口在多种角度下轴向静压因数的变化,并与平板型收集口对比.结果表明:收集口形状对轴向静压因数变化规律没有影响,轴向静压因数总是随开口角度的增大而减小;对于同一形状收集口,只在上方张开某一角度比在两侧张开相同角度的轴向静压因数略低.收集口角度变化对轴向静压因数会产生规律性影响:随收集口角度增大,从剪切层外部特别是上方进入到射流核心区的流量增加,导致核心区流速增加,从而导致轴向静压因数降低.

Effect of collector shape and angle on axial static pressure factor of automotive wind tunnel test section

To study the effect of collector shape and angle on the axial static pressure factor of automotive wind tunnel test section, the axial static pressure factor variation of airfoil type collector at different angles is researched with numerical simulation and test verification and compared with the panel type collector. The results indicate that, the axial static pressure factor variation law has nothing to do with collector shape and it always decreases with the increase of the opening angle; as to the same shape collector, the axial static pressure factor is a little lower when only the upper part of the collector is opened at a given angle than when the both sides of the collector is opened at the same angle. The collector angle changes have regular effect on the axial static pressure factor. With the collector angle increasing, the more flow enters the jet low core area from shear layer outside, especially from upper direction; it results in the increase of flow velocity in core area, which leads to the decrease of the axial static pressure factor.