二元高超声速进气道外压段阻力的理论分析及初步减阻研究

Theoretical Analysis on the Drag of Two-dimensional Hypersonic Inlet's External Compression and Initial Research on Reducing the Drag

为了给二元高超声速进气道的减阻研究提供理论指导,将反映动量损失的阻力与反映能量损失的总压恢复系数定量地关联起来,推导了二元高超声速进气道外压段阻力的理论公式,并用数值模拟方法初步考核了理论公式的普适性。在此基础上,以理论公式为依据,进行了外压段的初步减阻研究。结果表明:外压段阻力随总压恢复系数的增大而减小,提高总压恢复系数是减小阻力的有力途径;带小初始楔角的等熵压缩因其总压恢复系数较高、长度较短而成为外压段减阻设计的可行方案。初始楔角的等熵压缩阻力相对于楔压缩减小了;相对于纯等熵压缩只增大了,而长度却缩短了。

In order to provide guidance for the drag reducing investigation of two-dimensional hypersonic inlet.an initial equation for calculating the drag ooefficient of two-dimensional hypersonic inlet＇s external comperssion was edneed The equation gives out a dramatic relationship between the external compression drag and the total pressure recovery.It shows that, the drag will deoline when the total pressure recovery increases, therefore,improving the total pressure recovery coefficient is an efficient way to reduce the drag. Thereafter, an initial validation depending on CFD was performed to check whether the equation has a certain extent of popularity. Finally,according to the equation,an initial research for lowing the drag of external compression was performed, the result shows that, a small anglo ramp combined with isentropic scction is a feasible strategy for drag reduction of external compression.