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返回舱再入过程中,气动外形随着防热材料的烧蚀后退逐渐发生改变,可能对返回舱的再入性能带来不利反应。笔者前期对类联盟号返回舱在再入末段单个弹道点开展过烧蚀对配平特性的影响研究,为进一步研究烧蚀潜在的影响,通过烧蚀模型和吸热机理对类联盟号返回舱进行材料烧蚀计算,获得再入过程中4个不同时刻的烧蚀外形,它们的最大烧蚀量分别为2.3mm、7.8mm、9.8mm及12.5mm,在此基础上采用数值模拟方法对返回舱的烧蚀影响进行了研究,对初始外形和4个不同时刻的烧蚀外形分别进行气动特性的计算与分析,并与前期研究结果进行比较。结果显示:返回舱的烧蚀后退量将随着弹道的推移逐渐增大;烧蚀将使返回舱配平迎角减小(绝对值增大),配平升阻比增加,纵向压心前移,且这种影响随着烧蚀量的增加而增大;在研究范围内,配平迎角变化量与烧蚀后退量基本呈线性关系。该研究结果与文献对CEV乘员舱的研究结论在定性上是相符的,同时也验证了前期的研究结论。
During the reentry of the return capsule, the aerodynamic shape gradually changes with the ablation of the heat-resistant material and may adversely affect the reentry performance of the return capsule. In the previous study, the impact of ablation on the leveling characteristics of single-ballistic point of the Soyuz return capsule at the last reentry stage was studied. In order to further study the potential impact of ablation, the return of the Soyuz class through ablation model and endothermic mechanism The material ablation calculation was carried out to obtain the ablation profiles of 4 different times during the reentry process. The maximum ablation amounts of them were 2.3mm, 7.8mm, 9.8mm and 12.5mm, respectively. Based on this, numerical simulation was performed to return The ablation effect of the chamber was studied. The aerodynamic characteristics were calculated and analyzed for the initial shape and the ablation profiles at four different times respectively. The results were compared with the previous studies. The results show that the ablation volume of the return capsule will gradually increase with the trajectory. The ablation will reduce the rectilinear angle of return (absolute value), increase the ratio of drag-and-drag, forward pressure longitudinal, And this effect increases with the increase of ablation amount. In the research scope, the variation of the angle of attack and the angle of ablation is almost linear with the amount of ablation. The results of this study are qualitatively consistent with the conclusions of the study on the passenger compartment of CEV, and also verify the conclusion of previous studies.