流场稳定性及烧蚀时间对玻璃钢材料烧蚀性能的影响研究

STUDY OF THE STABILITY OF FLOW FIELD AND STUDY ON THE EFFECT OF ABLATION TIME ON ABLATION PROPERTIES OF FRP

本文以模压玻璃钢材料为研究对象,模拟材料高温烧蚀环境,以氧-丙烷焰流为热源,拟定测试方案,对材料进行烧蚀试验。探究在不同的热流密度值下,烧蚀距离对流场稳定性的影响,发现当热流密度值≥1.0 MW/m^2时,烧蚀距离改变,热流密度值波动较小,流场稳定性较好。探究烧蚀时间对玻璃钢材料烧蚀性能的影响,分析材料表面形貌变化的原因,发现随着烧蚀时间延长,质量烧蚀率明显下降,材料的线烧蚀率和质量烧蚀率一致性较差,这是因为在较短的烧蚀时间内,模压玻璃钢材料分层膨胀导致线烧蚀率较小,但薄弱的炭层结构会导致材料质量下降明显,质量烧蚀率较大。随着烧蚀时间从60 s升至120 s,材料分层积聚导致材料强度相对增大,抗冲刷能力增强,质量烧蚀率下降。并且在材料可承受的范围内,较长的烧蚀时间才能相对准确地反映材料的线烧蚀率。

In this paper,the molded FRP material was taken as the research object,the high temperature ablation environment of the material was simulated by the oxygen propane torch flame test.Drew up the experiment plan and then started the experiment to FRP.The influence of ablation distance on the stability of flow field was studied under different heat flux values.It was found that when the heat flux value was greater than 1.0 MW/m^2,the ablative distance had less influence on the fluctuation of heat flux value,and the stability of the flow field was better.The influence of ablation time on the ablative performance of FRP was explored,and the reasons for the change of the surface morphology of FRP were analyzed.It was found that with the prolongation of ablation time,the mass ablation rate decreased significantly,and the consistency between the linear ablation rate and the mass ablation rate was poor.This was because the layered expansion of the molded FRP during the shorter ablation time resulted in the smaller linear ablation rate,but the weak carbon layer structure would result in the decrease of the quality of the material obviously.So the mass ablation rate was high.With the increase of ablation time from 60 seconds to 120 seconds,the layered accumulation of materials lead to the increase of material strength.The enhancement of erosion resistance decreased the mass ablation rate.Within the acceptable range of materials,the longer ablation time can accurately reflect the linear ablation rate of the material.