大量附面层吸入S弯进气道内吹气控制

为了提高某大量附面层吸入的半埋入S弯进气道气动性能,采用数值模拟方法对其进行吹气控制研究并详细分析了吹气控制机理及吹气位置、吹气量、吹气角度变化对控制效果的影响.结果表明:吹气位置变化显著影响控制效果,最佳吹气位置位于气流分离点稍前的第1弯附近,该位置吹气比为1.75%、吹气角度为20°吹气时总压恢复系数相对原型提高约0.56%,出口周向总压畸变系数和旋流畸变系数分别下降约43.14%和83.60%;吹气角度并非越大越好,吹气时需尽量满足吹气角度较小,保证吹出的气流始终位于附面层内,避免与主流掺混而造成损失;总压恢复、出口周向总压畸变以及旋流畸变三者随吹气量变化的趋势不同,吹气量越大进气道总压恢复及总压畸变改善越明显,而旋流畸变随吹气量的增加先快速下降,随后变缓,最终甚至出现增加的趋势.

Blowing control in S-shaped inlet with significant boundary layer ingestion

Numerical simulation of blowing active flow control on a half flush-mounted S-shaped inlet was performed for improving its aerodynamic performance. The blowing control mechanism and influence of parameters (i.e. blowing location, blowing mass flow, blowing angle) variation on effect of blowing flow control were analyzed in detail. Results show that location selected for blowing has significant influence on effect of blowing, the 1st bend just before the separation point is the best blowing location. The total pressure recovery coefficient has a little rise about 0.56% and circumferential total pressure distortion coefficient and swirl distortion coefficient at exit reduce about 43.14% and 83.60% respectively in comparison with the prototype when blowing at 1st bend with blowing angle of 20° and ratio of blowing mass flow to air intake design mass flow about 1.75%. In addition, bigger angle doesn't mean better, on the contrary, little blowing angle should be selected for avoiding the high-energy air from pipes mixing with mainstream in the air intake. Moreover, blowing mass flow rise has different effects on total pressure recovery, circumferential total pressure distortion and swirl distortion. The improvement of first two becomes more obvious with the increase of blowing mass flow, while the third declines rapidly firstly, then falls slowly and even presents an increasing trend at last.