水雾热遮蔽过程的辐射与导热耦合换热

人工水雾对热辐射有着强烈的散射和吸收,可用于火灾安全和红外隐身。将水雾视为吸收、各向异性散射的灰体介质,考虑水雾的介质辐射、多重散射和环境的影响,利用窄谱带模型和Mie散射理论计算离散谱带的平均光学系数,将辐射传输方程和能量守恒方程耦合计算,建立了8~14微米红外辐射在水雾中衰减的计算模型。应用蒙特卡洛法与本文算法作对比,验证了模型的正确性；计算分析了目标在水雾遮蔽下的辐射强度场、热流密度散度以及对水雾温度场的影响；利用本文模型计算了光谱半球通过率,通过与朗伯比尔定律作对比,反映了介质辐射、多重散射、辐射热流等因素使得水雾遮蔽效率降低。

Coupled heat exchange of radiation and conduction of water sprays in the heat shielding process

Artificial sprays can be used in the fire safety and infrared stealth because that they can strongly attenuate the heat radiation through the scattering and absorbing effect. A model is established to calculate infrared radiation attenuated in the spray by coupling the radiation transfer equation and energy conservation equation. Taken the sprays as an absorbing, emitting, anisotropic scattering non-gray medium, the medium radiation, multiple scattering of the sprays, target radiation flux, and environment are taken into account. The radiative coefficients are calculated through Mie law and narrow bands approximation. The hemispherical spectral transmissivity is calculated with this model. By comparing with the Lambert-Beer's law, it was found that medium radiation, multiple scattering, and target radiation flux can weaken the spray shielding efficiency.