Abstract: In order to improve the seal and aerodynamic heating at the variable geometry throat section of RBCC inlet at high Mach number，an over/under type inlet was discussed by referring to the corresponding inlet that was previously applied to the TBCC.In the range of low Mach number，the inlet was adjusted to get a proper total contraction ratio and the same internal contraction ratio of each passage.Thus the two passages could gain similar performance parameters to reduce the mixing loss and resist the roughly same back pressure.In the range of high Mach number，the low-speed passage was closed and the high-speed passage was kept fixed.The numerical simulation results indicate when the free stream Mach number are 2.0，2.5，3.0，3.5，the average Mach number of the two throat and outlet sections are similar，the deviations do not exceed 0.05 and the mass flow rate reaches about 0.7.In summary，this design enables the inlet to possess a high mass flow rate and good performance during the whole working range Ma=2～6，and the adjusting method is practical and feasible.

Key words: RBCC inlet；Over/under type；Numerical simulation；Operating law

摘要： 为改善RBCC进气道在高马赫数下喉道段变几何部分的连接和气动热问题，参考外并联TBCC进气道的变几何方案，对RBCC进气道进行了外并联变几何研究。在低马赫数区间，通过调节使进气道获得合适的总收缩比和两通道的相同内收缩比，使得两通道喉道和出口截面的性能参数相近来减小掺混损失和达到相近的抗反压能力。在高马赫数区间，关闭低速通道，高速通道型面不变。数值模拟结果表明:在来流马赫数2.0，2.5，3.0，3.5下两通道喉道和出口截面的平均马赫数相差在0.05范围内，流量系数保持在0.7左右；在整个工作范围Ma=2～6内流量系数较高，总体性能较优，该变几何方案是正确可行的。

关键词: RBCC进气道；双通道；数值模拟；调节规律