齿冠形收敛喷管模型气动和红外辐射特性数值研究

针对齿冠形收敛喷管的气动和红外辐射特性进行了数值计算,并与常规收敛喷管进行了对比.在本文研究范围内的结果表明:①齿冠形收敛喷管的推力损失大于常规收敛喷管;②齿冠形尾缘引射外界大气与主流掺混的能力强于常规收敛喷管,核心区长度得到有效衰减;③齿冠形喷管的热喷流3～5μm红外辐射强度在侧向相对常规收敛喷管的衰减量在15%左右,尾缘内倾角对于尾喷流红外辐射强度衰减的影响甚微;④齿冠内倾时,尾向处能遮挡喷管内部热部件. 

Numerical research on flow dynamics and infrared radiation characteristics for scaled chevron convergent nozzle

Computational fluid dynamics/intercooled recuperated(CFD/IR) was numerically simulated to investigate the effects of the chevron structure on flow dynamics and infrared radiation characteristics of scaled turbofan engine convergent nozzle.The results based on the present parameters show that:(1) The total pressure loss and thrust coefficient loss are bigger in the chevron convergent nozzle than in the baseline case,these losses are weak with little tab inclined angles.(2) The chevron convergent nozzle could pump more secondary flow,and hence the core of plume for chevron convergent nozzle attenuates faster than the baseline nozzle.(3) The plume 3～5μm infrared radiation for the chevron nozzle along lateral direction is about 15% less than the baseline nozzle,the tab inclined angle makes no difference in the plume infrared radiation suppression.(4) The infrared shelter from the inner hot components appears when the chevron tabs incline inside,the 3～5μm infrared radiation for the chevron nozzle is reduced relatively by 10%～20% in comparison with the baseline nozzle along trailing direction.