跨超声速风洞扩散段流动分离控制设计参数研究

为抑制跨超声速风洞扩散段的分离,提出了一种较为完备的设计方法。由于影响扩散段性能的参数较多,完全通过试验方法进行设计的成本过高,该方法通过数值模拟,结合适当的边界条件,详细描述了扩散段角度、分流锥角度与长度、孔板开孔率对扩散段性能的影响;从数值模拟的结果可以看出,孔板开孔率和扩开角对扩散段性能有显著影响,通过比较得出较为合理的参数匹配,提高了扩散段的防分离性能,并改善了出口气流质量。数值结果与试验结果结论一致,表明本文所用的方法用于扩散段气动设计是可行的,为数值模拟方法应用于风洞部段气动设计创造了一定的条件。

Numerical simulations and experimental investigations of flow separation control in diffuser of transonic wind tunnel

A numerical simulation and experimental study was conducted to investigate a approach for controlling separation in wide angle diffuser (WAD) of transonic wind tunnel.WAD plays a vital role in the improvement of flow field quality in wind tunnel test section.Because of multitudinous parameters influencing performance of WAD,it is very difficult that design is only completed by experimental method.Basing on numerical simulations and experiments,the details were performed for different parameters influencing velocity uniformity of WAD outflow.It presented the control equations and boundary conditions for numerical simulation.Then the vortex wake length after conical taper were given using different inlet conditions,conical taper angle and bottom radius.Outlet velocity profiles and flow field details were shown in diffuser using different angle with different conical taper angle and open-area ratio of perforated plates.A transonic wind tunnel was used for the experiments.The numerical and experimental results were in accord with conclusions that reasonable parameters of WAD could significantly reduce or eliminate separation to produce more uniform velocity profiles entering setting chamber.It states the importance and feasibility of CFD in aerodynamical design of wind tunnel section.