激光对碳纤维增强复合材料的热烧蚀数值模拟

Simulation to thermal ablation of carbon fiber reinforced composites under laser irradiation

高能激光对复合材料的辐照效应研究,可以拓展激光技术的应用范围。为了预测激光辐照下碳纤维增强复合材料的瞬态热响应,提出了一个简化计算模型。采用隐式有限体积方法求解控制方程,边界条件包括激光辐照加热、对流换热、辐射换热以及材料表面烧蚀。考虑了激光辐照过程中基体热分解、质量迁移、比热容变化情况。基于该烧蚀模型,预测了激光辐照下碳纤维增强复合材料的瞬态温度场和表面烧蚀速率,计算结果与文献试验数据一致。最后,通过修正烧蚀模型分析了高速气流剥蚀对激光辐照复合材料热效应的影响。

The research on the laser irradiation effects of composites can expand the field of laser technique＇s application. A model was proposed to predict the thermal responses of carbon fiber reinforced composites under laser irradiation in time and space domain. An implicit finite volume method was used to solve the governing equation. The boundary conditions were considered in the model, including laser heat flow, heat convection, heat radiation and surface recession rate. The progressive changes in ther too-physical properties including decomposition degree, mass transfer, specific heat capacity, and thermal conductivity were de termined. The transient temperature and surface ablation rate of composites under laser irradiation were predicted, and the results were compared to experimental data. Finally the ablation model was modified to simulate the high-velocity airflow removed effects on composites.