单斜面膨胀喷管几何参数对流场和性能的影响

Investigation of the Influence of Single Expansion Ramp Nozzle Geometric Parameters on the Flow Field and Performance

基于CFD技术,通过求解R eynolds平均N-S方程附以标准k-ε双方程湍流模型,数值研究了单斜面膨胀喷管(SERN)主要几何参数对其内部流场和性能的影响,计算结果表明,SERN扩张段上、下斜面长度和角度对喷管流场结构和性能有明显的影响,随着上斜面长度的增加,喷管从欠膨胀状态过渡到过膨胀状态,在完全膨胀状态下,推力系数最大,存在某一最佳的上斜面角度,在该角度下,喷管推力系数最大,同样地,对于下斜面也存在最佳斜面长度和角度。

Based on CFD technology,the effects of major geometric parameters on performance of the single expansion ramp nozzle were numerically investigated by solving Reynolds average Navier-Stokes equations and standard two-equation k-ε turbulent models. The results show that upper ramp length, upper ramp angle ,lower flap length ,lower flap angle have evident effects on flow field structure and the performance of SERN. With the increase of upper ramp length,the expansion in SERN transits from under-expansion to over-expansion,thus an optimal upper ramp length is found to create maximal thrust coefficient. The upper ramp angle,lower flap length,and lower flap angle also have optimal values for SERN performance.