微射流强化混合对喷流红外辐射特性的影响

计算了微射流强化混合喷流在3~5μm波段的红外辐射特性,并与无微射流强化混合的喷流红外辐射特性进行了比较,分析了微射流强化混合对喷流红外辐射特性的影响.喷流的流场及温度场结果采用有限体积法求解N-S方程得到,采用Tam-Thies湍流模型模拟喷流.红外辐射特性的计算采用有限体积法求解吸收-发射性介质条件下的三维辐射传输方程得到.计算结果表明,在中等亚音速条件下,微射流可以达到较好的强化混合效果,射流流量占主流流量1%时,喷流的红外辐射强度比基准喷流的红外辐射强度降低15%左右,射流流量达到主流流量的3%时,喷流的红外辐射强度可以降低27%左右.

Effect of micro-jets mixing enhancement on infrared radiation of plume

The infrared radiation in 3~5μm band of the unforced plume and the forced plume which is mixed by injecting micro-jets into subsonic shear layer were calculated by a three-dimensional infrared(IR) radiation code of the plume, it was developed by the finite volume method (FVM) in non-gray absorbing-emitting media. The 3-D flow field of the jet was simulated numerically by FVM, Tam-Thies turbulence model. The results show that small injection flow rates (less than 3%) can make sharp increases in both velocity and temperature decay rates at middle Mach number. Compared with the unforced plume, when the jet mass flow accounts for 1% of the main flow, the IR radiation intensity of the forced plume is reduced by about 15%; and when the jet mass flow occupy 3%,the IR radiation intensity of the forced plume is decreased by about 27%.