高重频激光能量注入提高进气捕获率的数值研究

针对来流马赫数低于设计值时，吸气式冲压发动机进气道进气捕获率降低的问题，在唇口上游沉积高重频激光能量使气流偏折以提高进气捕获率。在马赫数为5.0、静压和静温分别为2 551.6 Pa和116.7 K的条件下，通过求解二维非定常可压缩RANS方程，数值研究了高重频激光能量注入提高进气捕获率的作用机制，通过在预想最优能量沉积点附近寻优的方法确定了最佳的能量注入点，结果表明:在该位置沉积频率100 kHz、平均功率500 W的激光能量形成的虚拟唇口可以使来流捕获率由63%提高至97%。结果证明了高重频激光能量注入提高进气捕获率的潜在应用价值，并为能量注入位置的优化选择提供了方法。

Numerical study on increasing mass flow ratio by energy deposition of high frequency pulsed laser

The mass flow ratio(MFR) of air breathing ramjet inlet would be decreased, when the Mach number is lower than the designed value. High frequency pulsed laser energy was deposited upstream of the cowl lip to reflect the stream so as to increase the MFR. When the Mach number of the flow was 5.0, and the static pressure and temperature of the flow were 2 551.6 Pa and 116.7 K, respectively, two-dimensional non-stationary compressible RANS equations were solved with upwind format to study the mechanisms of increasing MFR by high frequency pulsed laser energy deposition. The laser deposition frequency was 100 kHz and the average power was 500 W. The crossing point of the first forebody oblique shock and extension line of cowl lip was selected as the expected point. Then the deposition position was optimized by searching near the expected point. The results indicate that with the optimization of laser energy deposition position, the MFR would be increased from 63% to 97%. The potential value of increasing MFR by high frequency pulsed laser energy deposition was proved. The method for selection of the energy deposition position was also presented.