高超声速气动加热下战斗部装药热 -点火响应与典型结构热防护特性

Hypersonic warheads usually induce serious aerodynamic heating during flying, and the warhead charge also bears a harsh thermal environment because of the structural heating which may affect its thermal safety. The finite volume method and the two-way fluid-structure interaction method are used to simulate the aerodynamic heating and structural heat transfer processes of hypersonic warheads. The temperature field distribution of pneumatic heating of hypersonic warhead and the thermal-ignition response of charge at different speeds and angles of attack are analyzed based on the chemical reaction kinetics model of explosive. The results reveale that the highest temperature occurs at the head of the warhead under aerodynamic heating and structural heating transferduring the hypersonic flight of warhead, and then it decreases backwards and inward. The temperature distribution is asymmetrical at different angles of attack,the temperature on the windward side increases with the increase in the angle of attack, and the temperature on the leeward side decreases with the increase of the angle of attack. After introducing the chemical reaction kinetics model,the ignition of the charge appears on its head at 35. 4 s and 574 K. the faster the warhead's speed is,the more severe the aerodynamic heating it experiences is, and the shorter the ignition time of charge is. A thermal protection structure is designed, which can effectively increase the temperatures of warhead's shell and charge by 79. 12% and 71. 45% during its 100 s flight process as well as ensure that the internal charge does not ignite. This study is of great significance in addressing the thermal safety issues of hypersonic warhead charges.