舰炮身管的对流换热系数热化学计算方法

A Thermo-chemical Approach for Calculation of Convection Heat Transfer Coefficients in Naval Gun Barrel

火炮射击身管处于高温高压时,通过有限元热化学分析方法,输入参数,来获得对流换热系数的值。在沿火炮身管轴线方向,通过考虑火药燃烧速度、压力波速度、密度、燃烧气体混合物的热传导率的变化来评估雷诺兹和普朗特系数。这两个数值被用来计算努塞尔系数以确定不断变化的对流换热系数。它通过模拟发射过程和其相应的热化学有限元分析方法确定了这个系数,较好的反应了数值的真实性。

A finite element thermo-mechanical analysis of firing through a gun barrel requires the convection heat transfer co-efficient values under high temperature and pressure among input parameters. Considering the variable burning speed for a typ-ical gunpowder configuration, the variation of pressure wave speed, density, and heat conduction of the burning gas mixture are used to evaluate the Reynolds and Prandtl numbers along the barrel axis. These two numbers are then used to calculate the Nusselt numbers from which the continuously changing convection heat transfer coefficients are determined. It is confirmed from an experimental firing process and its corresponding thermo-mechanical finite element analysis that the calculated coeffi-cients present good estimate of the real coefficients.