充气式再入减速器动态气动载荷与结构特性研究

针对充气式再入减速器在动态飞行环境下的结构特性变化问题，提出一种基于飞行轨迹参数的CFD动态边界条件加载方法，有效实现了飞行动力学与空气动力学之间的耦合。同时，建立考虑内充压气体热效应的流固耦合模型，较已有方法更全面地考虑了结构变形对流场的影响以及内充压气体状态参数的改变，突破了现有研究中未能完整考虑温度对结构特性影响的局限。利用此模型着重对比了再入过程中气动力与气动热对结构应力及一阶固频的影响，并研究了尺寸变化对结构特性的影响规律。研究发现单独考虑气动力与气动热作用时，结构最大应力分别升高至39.6 MPa与33.5 MPa，而适当减小半锥角和增多气囊数目有利于减小结构应力。本文研究为充气式再入减速器的强度校核及优化设计提供了有价值的参考。

Dynamic Aerodynamic Load and Structural Characteristics of Inflatable Reentry Reducer

Aiming at the variation of the structural characteristics of an inflatable reentry reducer in dynamic flight environment, a loading method of CFD dynamic boundary by the flight trajectory parameters is proposed, which effectively realizes the coupling between the flight dynamics and the aerodynamics. At the same time, a fluid-solid coupling model considering the thermal effect of inflation gas is established, which considers the influence of structural deformation on flow field and the variation of the state parameters of inflation gas more comprehensively than the existing methods, breaking through the limitation that the influence of temperature on structural characteristics can not be fully considered in the existing research. The model is used to compare the effects of aerodynamic and aeroheating on structural deformation and first order frequency during reentry, and the influence of structural size on structural characteristics is studied. It is found that the maximal stress of the structure increases to 39.6 MPa and 33.5 MPa respectively when aerodynamic and aeroheating are considered separately, while reducing the half taper angle and increasing the number of gasbags properly are beneficial to reducing the stress during reentry. This study provides valuable reference for strength checking and optimal design of an inflatable reentry reducer.