氧乙炔与等离子烧蚀试验的系统评价研究

Research and Systematical Evaluation of Oxyacetylene and Plasma Ablation Tests

针对航天用复合材料烧蚀性能考核应用需求,本工作搭建了氧乙炔及等离子烧蚀热流密度测试平台,系统评价了影响烧蚀热流密度的主要因素,比较了两种烧蚀方式热流密度的差异,建立了烧蚀条件与热流密度的数学物理模型,提出了烧蚀热流密度的控制策略。结果表明:氧乙炔烧蚀及等离子烧蚀的热流密度均随烧蚀距离的缩短而增大,与烧蚀距离的倒数呈抛物线关系。距离较远时,氧乙炔烧蚀热流密度较大;距离较近时,等离子烧蚀热流密度超过氧乙炔。F4等离子喷枪烧蚀热流密度的变化规律与9M喷枪规律类似,但随着烧蚀距离、电流及辅气流量的变化更为显著。此外,辅气(H_(2))流量增加及电流增大均使等离子烧蚀热流密度增大。

Aiming to evaluate the ablation performance of aerospace composite materials,a heat flux testing device for oxyacetylene and plasma ablation tests was established in this work.The main factors affecting the ablative heat flux were systematically evaluated,and the differences between oxyacetylene and plasma ablation tests were compared.Mathematical and physical models of heat flux as a function of ablation conditions were deducted,and the control strategy was proposed for oxyacetylene and plasma ablation tests.Results show that the heat flux for oxyacetylene and plasma ablation tests increases with the decrease of ablative distance,and shows a parabola relationship with the reciprocal of distance.The ablative heat flux of oxyacetylene is higher than that of plasma ablation at a longer distance,but becomes lower at a shorter distance.The heat flux for F4 plasma torch is similar to the 9 M torch,but the change is more significant with the change of ablative distance,spraying current and auxiliary gas(H_(2))flow rate.Moreover,the increase of auxiliary gas flow rate and the spraying current also enhances the heat flux of plasma ablation.