加载波前沿宽度对铝表面微射流的影响

利用光滑粒子流体动力学方法，计算了金属表面沟槽在冲击下的微射流现象，详细讨论了微射流对加载波前沿宽度的依赖性. 计算结果表明：随加载波前沿宽度增加, 射流质量和头部速度都减小，同时低速喷射物所占比例增大. 对结果分析得出，微射流由沟槽斜面粒子在冲击加卸载后获得轴向速度，并在对称轴附近碰撞形成；射流体由沟槽斜面的金属薄层构成；当加载波前沿变宽，形成射流的金属层变小，这是由于沟槽斜面粒子的碰撞速度降低，碰撞角度增大，部分粒子碰撞时不满足射流强度封锁条件，而不再形成射流.关键词：微射流光滑粒子方法加载波前沿

Effect of loading-wave-front width on micro-jet from aluminum surface

With smoothed particle hydrodynamics, we calculate the formation of micro-jet from the groove of metal surface, and reveal the dependence on the width of loading wave front. The calculated results show that, with the decreasing loading speed,both the mass and the front velocity of ejection decrease, and the mass fraction with low velocity increases. We draw the conclusion that the formation of micro-jet is a result of the particles near the groove acquiring axial velocity and impacting at the axis, and the efflux derives from a layer near the groove. The thin layer becomes smaller when widening the wave front, which is because some particles can no longer satisfy the lock condition of jet strength with the decreasing impact velocity and the increasing impact angle, and then can jet no more.