非对称来流下带斜楔的短隔离段数值研究

Numerical investigation for the short isolator with a ramp under asymmetric incoming flow

关键词:  超燃冲压发动机  进气道  激波串  斜楔  壁面压力

Key words:  Scramjet  Inlet  Shock train  Ramp  Wall pressure

摘要:

为了提高超燃冲压发动机隔离段耐反压能力以及缩短其长度,设计了一种带斜楔的隔离段,斜楔放置在隔离段进口下壁面,对其进行了三维数值模拟,获得了带斜楔的隔离段耐反压能力特征以及缩短程度。通过数值模拟发现,隔离段加斜楔后能够承受的最大反压从来流静压的3.46倍上升到3.73倍,提高了7.8%左右。斜楔放置在厚附面层一侧更能改善隔离段耐反压性能。还发现加斜楔后可在进出口压比相同的情况下,将长度减小35%左右。

Abstract:

An isolator with a ramp was designed to improve the performance of the isolator or to reduce the length of the isolator. The ramp was placed on the lower wall at the isolator entrance. Computational fluid dynamics simulations were performed on the isolator. Numerical results indicated that the maximum back-pressure is improved by 7.8% for the isolator with a ramp which can withstand a maximum back-pressure of 3.73 times static pressure, but the isolator without a ramp could only withstand a maximum back-pressure of 3.46 times static pressure. The overall length could be reduced by 35% for the isolator with the ramp, and the ramp devices is more effective on the lower wall than on the upper one in improving the performance of the isolator.