壳体辐射物性参数对平流层飞艇热特性影响的研究

Researches on Thermal Characteristics of Stratospheric Airships Affected by Radiative Properties of Hull

建立了飞艇的传热数学模型,包括热平衡方程,太阳直射辐射、天空散射辐射、地面反射辐射、大气长波辐射、地球长波辐射、对流换热,以及飞艇内表面之间的辐射换热等。在此基础上,对平流层飞艇悬浮过程中壳体和浮升气体的温度变化进行了数值模拟,得到定点悬浮过程中平流层飞艇壳体的三维温度分布和飞艇浮升气体昼夜变化规律,重点分析了壳体辐射物性(太阳吸收率和发射率)对浮升气体温度昼夜变化和飞艇壳体温度分布非均匀性的影响,从而便于计算和分析由热问题引起的壳体应力,为飞艇壳体的选择和设计提供依据。

The mathematical models of heat transfer of airships are established, including thermal balance equations, direct solar radiation, dif- fuse radiation from the sky, reflected solar radiation from the Earth,infrared radiation heat transfer between the airship hull and the sky, infrared radiation heat transfer between the airship hull and the Earth, convective heat transfer, as well as radiation heat transfer between the dif- ferent parts of the interior surface of the airship hull. Based on the mathematical models, the temperature variations of a stratospheric airship hull and buoyancy gas are discussed. By numerical simulation, the temperature variation of the buoyancy gas and 3-D temperture profile of the stratospheric airship during station keeping have been presented. The effects of solar absorptivity and emissivity of the hull on the temperture variations of buoyancy gas and the non-uniform temperture distribution of the hull have been especially analysed. Heat stress can be calculated and analysed and it will provide a guide for selection and design of the hull.