通过将经典Busemann设计方法和特征线反设计方法相结合,实现了对基准Busemann流场的气动截短,构建了一种具有基准Busemann流场截短压升规律的可控消波内转基准流场.通过数值模拟对可控消波内转基准流场及其追踪得到的"糖勺"型进气道进行了无黏验证分析.结果表明:特征线和CFD计算结果相吻合,可控消波内转基准流场设计合理可行.该基准流场继承了Busemann设计方法的高效压缩特性,且反射激波得到有效控制,基本实现消波,性能优于传统的截短Busemann流场.在设计点马赫数为7条件下,喉部截面参数均匀,增压比为18.32,总压恢复系数为0.878,压缩效率为0.936,隔离段内几乎无损失,出口气流匀直,气流角均在±0.4°以内.流线追踪得到的"糖勺"型进气道出口形状更加饱满,流动特征与可控消波内转基准流场基本一致.
An inward turning basic flowfield with controlled and cancelled shock waves was proposed based on Busemann pressure rise distribution by combining the method of Busemann design and method of characteristics.By this method,the aerodynamic truncation of the basic Busemann flowfield was realized.Then the inward turning basic flowfield with controlled and cancelled shock waves and a streamline traced sugar-scoop inlet were numerically simulated by inviscid CFD.The results show that the flowfield results solved by method of characteristics agree well with CFD,indicating that the inward turning basic flowfield with controlled and cancelled shock waves is reasonable and feasible.It inherits the high compression efficiency of Busemann design and keeps the reflected shock waves under control,and the shock cancellation is almost achieved,so it performs better than the classical truncated Busemann inlet.At the design point of Mach number 7,the flow parameters of throat section are uniform,with a pressure ratio of 18.32,a total pressure recovery coefficient of 0.878 and a compression efficiency of 0.936.There is almost no reduction of total pressure in isolator.The outflow is straight and uniform and the flow angle deviation is all within ±0.4 degree.The traced sugar-scoop inlet has a more circle-like outlet and inherits the characterisitics of inward turning basic flowfield with controlled and cancelled shock waves.