太阳辐射下狙击枪枪管附近流场及其热变形分析

为了预测太阳辐射下狙击枪枪管的变形程度，以某型狙击步枪为基础，在CFX与ANSYS中建立了空气与枪管的瞬态热流固耦合计算模型，求解枪管与外界的对流换热系数。计算得到3 h内枪管附近对流换热流场情况、枪管温度场变化以及最终枪管变形程度，分析枪管周围流动换热结果和枪管热变形结果，显示太阳辐射作用下枪管周围会产生显著热对流效应，热气流上升最终产生复杂的大气湍流运动影响了枪管周围的对流换热，对流换热系数明显不是定值。分析结果表明：辐射导致的温差与自重耦合作用下枪口弯曲角可达约0.3 mil，将对狙击步枪的射击精度产生明显影响。该研究为该类狙击步枪枪管受太阳辐射导致的热变形提供数值预测方法。

Flow Field and Thermal Deformation Analysis of Sniper Barrel Under Solar Radiation

The estimate of sniper rifle barrel deformation under solar radiation highly depends on accurate convective heat transfer coefficient. Based on a certain sniper model, a transient thermal fluid-solid interaction calculation model of a sniper barrel and nearby air had been built in CFX and ANSYS. The convection heat flow field around barrel, temperature variation and final deformation of barrel within 3 hours were obtained. Calculation results showed that there was obvious convection flow around barrel under solar radiation, complex turbulent air flow would be formed under continuous upper hot flow, this affected convection around barrel. The bending angle at barrel muzzle could reach 0.3mil under the coupling effect of temperature difference resulting from solar radiation and the barrel weight itself, which had obvious effect on shooting accuracy of sniper rifle. So the results will provide a numerical prediction solution for the sniper barrel deformation under solar radiation.