磁场方向对圆筒结构内高温导电气体流动与传热特性的影响研究

Effect of Magnetic Field Direction on the Flow and Heat Transfer Characteristics of High Temperature Conductive Gas in Cylinder Structure

火药气体在高温环境下会发生电离形成热等离子体,从而具有良好的导电性。针对高温火药气体对武器身管产生热烧蚀的问题,提出一种应用磁控等离子体降低身管内膛表面温度的方法。运用磁流体描述法构建高温导电气体在圆筒结构中的湍流耗散模型,研究了不同磁场方向对导电气体黏性效应及腔体壁面温度的影响,并采用红外热成像技术测试了同轴磁场对导电气体传热特性的影响。结果表明:与流动方向相垂直的磁场,可以有效地降低导电气体的湍流动能和湍流黏度,削弱其传热能力,并且流动分布出现各向异性特征,沿磁场方向的湍流动能和湍流黏度要低于垂直磁场方向;施加同轴磁场可以限制带电粒子的径向扩散,减少导电气体对圆筒壁面的传热量,从而降低壁面温度。

The propellant gas is ionized to form thermal plasma at high temperature, which has good con- ductivity. For the problem of thermal ablation of weapon barrel by high temperature propellant gas, a method to reduce the surface temperature of barrel bore by using magnetron plasma is presented. A turbu- lent dissipation model of high temperature conductive gas in cylinder structure is constructed by using the magnetic fluid description method. The influences of different magnetic field directions on the viscosity effect of conductive gas and the wall temperature of cavity are studied. The effect of coaxial magnetic field on the heat transfer characteristics of conductive gas is tested by infrared thermal imaging technology. The results show that magnetic field which is perpendicular to the direction of flow can effectively reduce the turbulent kinetic energy and turbulent viscosity of conductive gas and weaken its heat transfer capability, the flow distribution has the anisotropy characteristics, and the turbulent kinetic energy and turbulent vis-cosity along the magnetic field direction tic field. The coaxial magnetic field can transfer of conductive gas to the wall of are lower than those in the direction perpendicular to the magne- limit the radial diffusion of charged particles and reduce the heat cylinder, thereby reducing the wall temperature.