反应性气膜对喷管附面层损失的影响

Influence of reactive gas film on nozzle boundary layer loss

针对二维轴对称喷管,数值模拟研究了氢气和正癸烷两种反应性气膜对喷管附面层损失的影响,分析对比了喷注比为0%、0.47%、1.07%、1.42%以及氢气、正癸烷两种不同喷注物质下喷管附面层损失变化规律。结果表明,与无喷注的情况相比,壁面喷注形成的反应性气膜显著降低了喷管壁面温度;当喷注比从0%增加到1.42%时,氢气反应性气膜使得喷管扩张段壁面平均温度降低了2648.3 K,而正癸烷反应性气膜使得喷管扩张段壁面平均温度降低了1875.9 K;喷注物质为正癸烷不利于降低喷管附面层损失,正癸烷反应性气膜使得喷管附面层损失增加了504.3%;而喷注物质为氢气更有利于降低喷管附面层损失,反应性气膜使得喷管附面层损失降低了38.8%。研究表明,氢气反应性气膜对喷管的热防护和附面层减阻综合性能提升更有利。

Aiming at the two-dimensional axisymmetric nozzle,the effect of reactive gas film of hydrogen and n-decane on the nozzle boundary layer loss was investigated by numerical simulation.For the two different injection materials,the boundary layer loss of nozzle under different injection ratios of 0%,0.47%,1.07% and 1.42% were analyzed and compared.The results show that the reactive gas film formed by the wall injection significantly reduces the nozzle wall temperature compared to the non-injection case.When the injection ratio increases from 0% to 1.42%,the hydrogen reactive gas film makes the average wall temperature of the nozzle expansion section reduced by 2648.3 K.However,the n-decane reactive gas film causes the average wall temperature of the nozzle expansion section to decrease by 1875.9 K.The n-decane injection is not beneficial to reduce the boundary layer loss of the nozzle,which increases the nozzle boundary layer loss by 504.3%.Meanwhile,hydrogen injection is conducive to reducing the nozzle boundary layer loss,which reduces the boundary layer loss by 38.8%.Therefore,the hydrogen reactive film is more beneficial to improve thermal protection and drag reduction of nozzle boundary layer.