疏导式结构在头锥热防护中的应用

Application of leading structure on thermal protection of nosetip

针对高超声速飞行器工作时头锥恶劣的热环境,为了保证飞行器头锥的尖锐外形,提出疏导式热防护结构,利用内置高导热碳材料结构为飞行器头锥提供热防护.采用流固耦合方法对头锥疏导式防热结构进行了分析,验证了头锥内置高导热碳材料具有较好防热效果,其中来流马赫数(Ma)为9时头锥前缘壁面最高温度下降了21.9%,尾部最低温度升高了15.2%,实现了热流由高温区向低温区的转移,削弱了头锥的热载荷,强化了头锥的热防护能力.本文对外蒙皮结构参数、材料参数以及内部高导热碳材料导热率对头锥热防护性能的影响进行了分析,其中头锥最高温度随着蒙皮材料导热系数的增加而降低到一个稳定值;随着蒙皮材料表面黑度的增加而降低;随着蒙皮厚度的增加而升高;随着高导热碳材料导热系数的增加而呈抛物线下降.

The structure of embedded high thermal conductivity carbon material leading thermal protection is considered as thermal protec-tion system to prevent hypersonic vehicle nosetip which＇ requires sharp figure during hypersonic flying, from being seriously aerody- namically heated. By fluid structure interaction method, we analyze leading thermal protection of nosetip and validate that embedded high thermal conductivity carbon material structure has a good effect on thermal protection. The maximal temperature of the nosetip which uses leading thermal protection structure is reduced by 21.9% and the lowest temperature of aft is increased by 15.2% when Mach number is 9. The transfer of heat from head to after-body is achieved, the thermal load of the front head is weakened and the ability of leading-edge thermal protection is strengthened. The influences of structure parameter and material attributes of coating and thermal conductivity of high conductivity carbon material on thermal protection are discussed. The highest temperature of the nosetip decreases with thermal conductivity of coating increasing to a steady value and descends with blackness level of coating ascending and increases with the thickness of coating increasing, and it descends in parabola form as thermal conductivity of carbon materials increases.