一级锥可调变几何轴对称进气道初步研究

为了改善轴对称进气道的攻角特性,提出一种简单易实现的轴对称变几何方法:通过旋转轴对称进气道第1级压缩锥改变进气道前体激波的角度和位置.采用数值仿真方法研究了来流马赫数为3和4时,不同飞行攻角条件下一级锥可调变几何进气道的三维流场和性能特性,并与定几何进气道进行对比分析.结果表明:大攻角下,采用一级锥可调进气道除了可以提高进气道的质量流量系数外,还有效缓解了背风侧低能流堆积问题；存在一个最佳的旋转角度,使该攻角下进气道性能最高；随着攻角的增大,所需的旋转角度增大,进气道所获得的性能增益也随之提高,在马赫数为3,攻角为14°时推力增益达到7.7％.

Preliminary study on variable-geometry axisymmetric inlet with first cone pivoting

To achieve good characteristics of an axisymmetric supersonic mixed-compression inlet at different angles of attack,a feasible and available variable-geometry technique was proposed and demonstrated by changing the shock system structure of the forebody with a pivoting first cone.The 3-D flow field and performance characteristics of the variable-geometry inlet at Mach 3 and 4 were investigated numerically over a wide range of angles of attack,and the results were compared with those of the conventional fixed-geometry inlet.The results indicate:(1) By rotating the first cone,the mass flow coefficient of the inlet is improved and the low-energy flow accumulation at the leeward side is relieved effectively at high angle of attack.(2) There exists an optimum value of the angle of rotation,enabling the inlet to reach the highest performance at given high angle of attack.(3) With the increase of angle of attack,the optimum angle of rotation increases,and the thrust augmentation also increases to 7.7% at Mach 3 and angle of attack of 14°.