强激光加热旋转薄柱壳的参量选择分析

为了把激光加热静止圆柱壳的实验测量结果应用到旋转圆柱壳的激光参量估计中,研究了旋转圆柱壳的激光加热效率。用积分变换法得到了旋转圆柱壳的温度分布,分析了最大温升点相对激光峰值强度点的滞后现象。基于静止圆柱壳和薄壳假设,导出了旋转圆柱壳激光加热效率及估计辐照时间的表达式。对于旋转金属圆柱壳,最大温升点相对激光峰值强度点的滞后角和激光加热效率取决于无量纲参量DR(柱壳半径R与束斑半径r0之比)、DL(横向热扩散尺度4ατL与束斑半径r0之比)及DM(加热时间τL与柱壳旋转频率fR的乘积)。达到相同的最大温升时,旋转圆柱壳的激光辐照时间和静止圆柱壳的激光辐照时间之间存在与激光功率无关的非线性关系,而激光功率决定了所需的绝对激光辐照时间。

Analysis of the Laser Parameters Choice for a Rotational Thin Cylinder Shell under CW-Laser Irradiation

The heating efficiency for a rotational cylinder shell under CW-laser irradiation is studied. An analytical expression for temperature profile, obtained by integral transforms method (ITM), is utilized to analyze the lag-phenomenon of the maximum temperature rise position relative to the laser peak-intensity position on the shell surface. The expressions of the heating efficiency and the lag-angle are obtained. The results show that the heating efficiency and the lagangle are dominated by three dimensionless parameters: DR (the ratio of cylinder shell radius to R laser spot radius r0), DL (the ratio of thermal diffusion length 4ατL to laser facular radius r0), and DM (the product of irradiation time τL and shell rotation frequency fR). If the same maximum temperature rise arrives to arrive at, there exists the nonlinear relation between the required laser irradiation times for a rotational cylinder shell and for a still cylinder shell, and is independent of the laser power, and the laser power determines the required absolute irradiation time.