旋翼气动加热对直升机红外特征分布的影响

文中采用数值模拟的方法较为系统地研究了旋翼表面温度分布及其对直升机红外辐射特征分布的影响。结果表明:（1）旋翼桨叶上自旋翼转轴到翼尖温度分布呈依次递增的趋势，最高温度值为316K，高出环境温度29 K；遮挡罩表面最高温度值为317 K，高出环境温度30 K；（2） 探测角度一定时，旋翼红外辐射强度随时间上下波动， 旋翼在3～5 m 和8~14 m 波段红外辐射强度随时间的变化趋势基本一致；（3） 旋翼气动加热后3～5 m 波段和8~14 m 波段红外辐射强度值的增量占整机固体对应波段总的红外辐射强度的比重分别为15%～16%、5%～6%；（4）同一发射率下，气动加热的旋翼8~14 m 波段红外辐射强度远大于3～5 m 波段，约为3～5 m 波段辐射强度的30 倍，其8~14 m 波段红外辐射强度约占整机固体8~14 m 波段红外辐射强度的30%~40%， 但降低旋翼表面发射率能有效降低旋翼8~14 m 波段红外辐射强度，同时也能降低旋翼辐射占整机辐射的比重。

Influence of rotor aerodynamic heating on infrared characteristics of the distribution of the helicopter

Based on CFD/IR numerical calculations, the temperature distribution of rotor skin and the effect on the infrared radiation characteristics of helicopter were studied systematically. The results show that: (1) The temperature distribution on the rotor blades shows an increasing tendency from the rotor shaft to wingtip, the maximum temperature is 316 K, 29 K higher than the ambient temperature; The maximum temperature of radiation shield is 317 K, 30 K higher than the ambient temperature; (2) At the same detection angle, rotor infrared radiation intensity fluctuates along of time, the change of infrared radiation intensity with time in 3-5 m and 8-14 m bands is consistent; (3) The proportion of 3-5 m and 8-14 m band infrared radiation intensity increment of aerodynamic heating rotor in the same band infrared radiation intensity of overall solid are 15%-16%、5%-6%; (4) 8-14 m band infrared radiation intensity of aerodynamic heating rotor is about thirty times as much as that of 3-5 m band, the proportion of aerodynamic heating rotor 8-14 m band infrared radiation intensity in the same band Based on CFD/IR numerical calculations, the temperature distribution of rotor skin and the effect on the infrared radiation characteristics of helicopter were studied systematically. The results show that: (1) The temperature distribution on the rotor blades shows an increasing tendency from the rotor shaft to wingtip, the maximum temperature is 316 K, 29 K higher than the ambient temperature; The maximum temperature of radiation shield is 317 K, 30 K higher than the ambient temperature; (2) At the same detection angle, rotor infrared radiation intensity fluctuates along of time, the change of infrared radiation intensity with time in 3-5 m and 8-14 m bands is consistent; (3) The proportion of 3-5 m and 8-14 m band infrared radiation intensity increment of aerodynamic heating rotor in the same band infrared radiation intensity of overall solid are 15%-16%、5%-6%; (4) 8-14 m band infrared radiation intensity of aerodynamic heating rotor is about thirty times as much as that of 3-5 m band, the proportion of aerodynamic heating rotor 8-14 m band infrared radiation intensity in the same band infrared radiation intensity of overall solid is about 30%-40%, but reduction of rotor surface emissivity is the effective method to reduce the 8-14 m band infrared radiation intensity and the proportion in the same band infrared radiation intensity of overall solid.