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在实验数据验证的基础上,通过计算流体力学/红外辐射(CFD/IR)综合的方法,对不同落压比、不同几何矢量角下的单边膨胀喷管(SERN)进行分析。研究结果表明:喷管无几何矢量动作下,低落压比下的单膨胀边上过度膨胀是造成喷管推力性能急剧下降的原因;喷管在负矢量角下,过度膨胀加剧,推力性能降低;随着喷管几何矢量角绝对值的增加,矢量推力增加,但推力系数减小,喷管几何矢量角在±25°、喷管落压比在3～6的研究范围内,喷管推力系数最低为0.88左右,最高达0.98;喷管几何矢量角为5°时,喷流红外辐射强度最大,喷管矢量角偏离5°的程度越大,尾焰红外辐射强度越低,但是空间分布规律不变。随着喷管几何矢量角的改变,喷管整体红外辐射强度的空间分布规律发生改变,几何矢量角为负时,辐射强度值大的探测角度向下方移动,几何矢量角为正时,喷管整体红外辐射较强的位置分布在上方,由单膨胀边高温壁面以及喷管内腔的可视面积决定。
Based on the experimental data, a single-sided expansion nozzle (SERN) with different pressure ratios and geometrical vector angles was analyzed by CFD / IR method. The results show that under the geometric vectorial motion of the nozzle, the over-expansion on the single expansion side under the low pressure-drop ratio causes the sharp drop of the thrust performance of the nozzle. The excessive expansion of the nozzle under the negative vector angle reduces the thrust performance. With the increase of the absolute value of nozzle geometric vector angle, the vector thrust increases but the thrust coefficient decreases, the geometric angle of the nozzle is within ± 25 ° and the nozzle drop ratio is within the range of 3 to 6. The thrust coefficient The minimum is about 0.88 and the maximum is 0.98. When the geometric vector angle of nozzle is 5 °, the intensity of infra-red radiation of jet is the largest. The larger the degree of divergence of nozzle vector is from 5 °, the lower the intensity of infra-red radiation is, but the spatial distribution constant. With the change of geometric vector angle of nozzle, the spatial distribution regularity of the overall infrared radiation intensity of the nozzle changes. When the geometric vector angle is negative, the detection angle with large radiation intensity moves downward. When the geometric vector angle is positive, The location of the overall strong infrared radiation distribution in the top, by the single expansion side of the high temperature wall and nozzle cavity visible area decision.