专用跨声速风洞开孔壁试验段设计数值模拟

 在跨声速范围内,战斗机内埋式武器弹舱流场具有强烈的非定常特征。为获得准确的试验数据,需要对我国唯一的2 m量级以上的2.4 m×2.4 m引射驱动式跨声速风洞开孔壁面试验段进行适应性改造。通过采用计算流体力学(CFD)数值模拟方法对引导风洞试验段设计方案进行评估优化,以获得最佳设计结果。与采用马赫数为1.4的喷管和开孔壁面试验段时的试验结果相比较,文中采用的开孔试验段壁板边界条件能获得较为准确的流场特性。对设计方案的数值研究结果表明,前过渡段的收缩与扩张降低了试验段气流质量,后过渡段引射缝开度明显影响分离特性,对前过渡段开孔率分布规律的优化使试验段流场均匀性达到了试验要求。

Numerical Simulation of Design of Transonic Wind Tunnel Perforated Test Section

The flow field related to the interior weapons bay of a combat aircraft is associated with strong unsteadiness effects in the transonic range.The perforated test section of a 2.4 m×2.4 m injection driven transonic wind tunnel,whose test section caliber is China’s only one larger than 2 m,is redesigned so as to obtain more accurate experimental data.Striving for the best design,attempts are made using computational fluid dynamics(CFD) analysis to evaluate and optimize the preliminary design project of a pilot wind tunnel.The boundary conditions of the perforated test section wall are validated by comparing with the experiment results at Mach number Mat=1.4,and then used for simulations of several projects.The current research reveales that the flow characteristics are greatly influenced by the entrance transition section and outlet transition section.The contraction and expansion of the entrance debase flow quality.The attitude of the injection flaps determines the size of the separation area.Then different models using different open-area ratios of perforated wall at entrance are investigated based on the numerical results.Desired flow quality is obtained when the transition section adoptes reasonable open-area ratios.