跨声速风洞专用开孔壁试验段实验研究
Experimental research of special perforated wall test section for transonic wind tunnel
-
摘要: 为满足型号试验需求,2.4 m×2.4 m跨声速风洞需在不改变现有洞体结构和安装条件下新研制一个截面尺寸为3 m×1.92 m(宽×高)的专用开孔壁试验段。为了降低技术风险和投资风险,以0.24 m×0.20 m跨声速风洞(2.4 m×2.4 m跨声速风洞的引导风洞)为实验平台,采用变截面气动设计方案新设计、加工了一个专用开孔壁试验段实验件,并开展了预先性实验研究工作。通过实验研究验证了专用开孔壁试验段气动设计方案可行,且试验段模型区内流场达到设计指标要求。实验还考察了壁板扩开角、主流引射缝开度、开孔率分布等参数对流场均匀性的影响,研究结果表明:在扩开角0.3°、引射缝开度12 mm、加速区采用递增方式开孔时,专用开孔壁试验段的流场能够满足马赫数均方根偏差σM≤0.01(0.4≤Ma<1.0)、σM≤0.02(1.0≤Ma≤1.2、1.4)设计指标要求,并且在Ma≤1.0时,σM达到了国军标合格指标要求。研究工作为2.4 m×2.4 m跨声速风洞专用开孔壁试验段设计提供了技术支持,也为该风洞下一阶段调试和流场校测提供了可供参考的调试参数。Abstract: The perforated test section of the 2.4 m×2.4 m injection driven transonic wind tunnel is redesigned so as to study the aerodynamic force of advanced aircraft. A scaled experimental research of the special perforated wall test section is conducted in the 0.24 m×0.20 m transonic wind tunnel (the pilot wind tunnel of the 2.4 m×2.4 m transonic wind tunnel). The experimental study has demonstrated that the project is feasible, and the flow quality of the flow field in the special perforated wall test section reaches the required specification. Influences of the diffuse angle in the test section, the open width of the mainstream ejected slot and the porosity of the perforated wall are also investigated. The results have been used to design the perforated test section of the 2.4 m×2.4 m transonic wind tunnel. The calibration parameters for the future perforated test section flow field calibration in this tunnel are also provided.