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采用Roe通量差分分裂格式对带有小突片的轴对称收 扩喷管内外流场进行了数值模拟。小突片形状有三角形和梯形 ,数目为 2个或 4个 ,堵塞比为 0 0 2 ,0 0 4和 0 0 6 ,相对高度为 0 0 8和 0 16 ,安装角分别为 12 0° ,135°和 15 0°。计算结果表明 :在喷管出口安装 2个或 4个小突片能使得喷管下游内外流掺混时间及掺混距离大为缩短 ,而对喷管的推力系数影响不大。采用小突片对于降低喷流噪声和抑制尾喷流红外辐射是非常有利的
The Roe flux differential split scheme is used to simulate the flow field inside and outside the axisymmetric convergent and divergent nozzle with small tab. The shape of the tab is triangular and trapezoidal, the number is 2 or 4, the plugging ratio is 0 0 2, 0 0 4 and 0 0 6, the relative height is 0 0 8 and 0 16, the mounting angles are respectively 12 0 °, 135 ° and 15 0 °. The calculation results show that installing two or four small tabs at the exit of the nozzle can shorten the mixing time and the mixing distance of the inner and outer flow downstream of the nozzle greatly, but has little effect on the thrust coefficient of the nozzle. The use of small tabs is very advantageous for reducing the jet noise and suppressing the jet of tail jet