增强型电磁轨道炮瞬态温升时空分布

Spatial-temporal Distribution of Transient Temperature Rise in Augmented Electromagnetic Railgun

轨道瞬态温升时空分布特性对于增强型电磁轨道炮发射效率具有极其重要的作用。该文从接触电阻瞬态特性、枢轨接触压力瞬态特性的角度,对轨道电阻焦耳热与摩擦热共同影响轨道瞬态时空温升的分布特性进行研究。通过发射试验得到的炮口电压、轨道电流、电枢位移等数据建立这几个物理量之间的数学模型,计算分析了增强型电磁轨道炮枢轨接触电阻瞬态特性,获得了轨道接触电阻焦耳热分布;应用瞬态接触压力计算方法模拟枢轨接触压力的瞬态特性,获得了轨道摩擦热分布。为研究轨道瞬态温升时空分布特性,通过电枢运动位移、速度与时间的关系,对轨道进行分段建立瞬态温度场计算模型并采用电-磁-热耦合的计算方法,得到了以电阻焦耳热与摩擦热为热载荷共同作用下的轨道温升时空分布特性。数值模拟结果表明:随着电枢高速运动,摩擦热随之逐渐上升,接触电阻热较小;发射过程中临近炮尾的轨道温升较大,表明了炮尾轨道为热管理的关键部位,为电磁轨道炮的热设计提供了理论依据。

The temperature spatial-temporal distribution of railgun play an extremely important role in increasing the efficiency of electromagnetic railgun launch. The temperature spatial-temporal distribution of railgun under resistance joule heat and friction heat is studied from the point of contact resistance transient response and contact pressure transient response. A mathematical model is established through the muzzle voltage, rail current, and armature displacement obtained by launching experiments. The characteristics of resistance transient are analyzed to obtain the resistance joule heat in rail. The transient contact pressure calculation method is employed to simulate the transient contact pressure and to obtain the friction heat in rail. In order to explore the temperature spatial-temporal distribution of railgun, the spatial-temporal distribution characteristics of rail temperature under thermal load of resistive heating and frictional heating are obtained by electromagnetic and thermal coupling methods, in which the relation between displacement, velocity and time is taken into consideration. The results of numerical simulation indicate that friction heating will increase gradually as the armature moves at a high speed. Temperature rises rapidly in the rail near breech, indicating the rail breech is the critical areas for thermal management. The results can provide the theoretical basis for the thermal design of railgun launcher.