Analysis of sublimation-cooled coated mirrors in convective and radiative environments.
Analysis of sublimation-cooled coated mirrors in convective and radiative environments.
复制标题
对流和辐射环境中升华冷却镀膜镜子的分析。
DOI：
10.2514/3.6673
复制
发表时间：
1973
期刊：
影响因子：
2.5
通讯作者：
M. J. Green
中科院分区：
文献类型：
--
作者：
J. Howe;M. J. Green
得到了发汗冷却或升华冷却球面镜膜在对流加热和辐射加热作用下的热响应解析解。这些解决方案允许考虑到无限的光谱细节。结果表明，对于内吸收系数为0.01/cm的石英类材料，发汗冷却的厚涂层(1 Cm)可以稳定地承受高达10kW/sq cm的温度，而不会出现过高的温升。对于吸收系数为0.1每厘米的材料，瞬时可容纳高达20千瓦/平方厘米的流量1秒(连续激光曝光时间)、4千瓦/平方厘米的流量5秒(行星入射加热时间)、毫秒量级的毫瓦/平方厘米(短持续激光脉冲)而不发汗冷却。相对较高的通量可以与较低的吸收系数相适应。热脉冲产生的热应力很高，但在材料的强度范围内。对可能获得有意义的解决办法的制度进行了详细的描绘。
Analytical solutions were obtained for the thermal response of a transpiration- or sublimation-cooled spherical mirror coating exposed to convective and radiative heating. The solutions allow unlimited spectral detail to be accounted for. Results indicate that transpiration-cooled thick coatings (1 cm) may withstand up to 10 kW/sq cm on a steady basis without excessive temperature rise for quartzlike materials with an internal absorption coefficient of 0.01 per cm. On a transient basis, fluxes up to 20 kW/sq cm can be accommodated for a second (cW laser exposure time), 4 kW/sq cm for 5 sec (planetary entry heating time), and of the order of MW/sq cm for millisecond times (short-duration laser bursts) without transpiration cooling for a material with an absorption coefficient of 0.1 per cm. Proportionately higher fluxes can be accommodated with lower absorption coefficients. Thermal stresses produced by the heat pulse are found to be high but within the strength of the materials. The regime in which meaningful solutions may be obtained is mapped in detail.