节点文献
可重复使用运载器热防护系统性能分析研究
Reusable Launch Vehicle Thermal Protection System Performance Study
【作者】 马忠辉;
【导师】 孙秦;
【作者基本信息】 西北工业大学 , 飞行器设计, 2004, 博士
【摘要】 先进热防护系统(TPS)的设计是决定可重复使用运载器(RLV)成败的关键技术之一。目前我国在可重复使用运载器的各项研究工作刚刚起步,缺乏热防护系统的理论研究。作为可重复使用热防护系统研究的组成部分及国内系统进行热防护系统研究的起步工作,本文主要进行TPS的传热研究及相关性能分析。 TPS设计是质量优化的结果,可重复使用运载器外表面所需的TPS质量主要由传热分析确定。本文根据TPS热防护系统设计涉及到多种结构形式、传热机理以及复杂的防热结构/材料的合理选择布置等特点,将TPS热分析研究划分为两个层次,即整个热防护系统的设计与性能分析及典型防热结构的设计与性能分析。通过建立简化程度不同的热分析模型,即一般TPS热分析模型及典型结构热分析模型,用以实现大面积TPS瞬态温度响应分析、TPS质量预测及具体防热结构/材料的传热细观设计。这一分析方法既可完成精细程度不同的分析任务又提高了分析效率。 按照一般TPS热分析模型在热分析模型组织中的作用,本文依据TPS在再入过程中的传热特点,对TPS真实结构进行了均质化假设,建立了适合于任何TPS的一维瞬态传热分析模型及与之相对应的质量模型。一般TPS热分析模型应用于各部分结构的宏观表征和性能分析,不再体现各部分结构的细观结构特征。针对一般TPS热分析模型的特点,应用有限差分法建立了非线性全隐式格式一维瞬态传热数值分析模型。本文建立的一般TPS热分析模型满足了TPS设计中大面积分析设计的使用要求,使全机范围内TPS瞬态传热分析及TPS质量预测可行。 本文将完整热防护系统的各层功能及形态各异的结构/材料视作典型结构,对四种具有良好应用前景的典型结构类型,即刚性陶瓷防热瓦/柔性隔热毡、多层隔热结构、金属多层壁结构及蜂窝面板结构的传热机理进行了详细分析,对其结构形态及传热过程进行了一维或二维简化,建立了各典型结构的传热数学分析模型,细致表现了各结构的细观结构特征及传热特点。根据各模型的结构特点,分别采用有限元或有限差分方法建立了各典型结构瞬态、稳态传热数值计算模型,并应用数值计算对影响各典型结构防热、隔热性能及瞬态温度响应特点的主要细观参数进行了详细分析,获得了若干具有指导结构优化设计的参数选取规律。 本文最后对TPS的总体方案优化设计进行了初步的探讨。应用本文建立的热
【Abstract】 The unique function of the thermal protection system(TPS) is to maintain the vehicle structural temperature within allowable limit during re-entry aerodynamic heating, which is critical to a new generation of reusable launch vehicles(RLV). Some countries, such as USA, Russia, France etc, have fruitful research experience and are developing more excellent TPS. But in our country, all aspects of research of RLV are just beginning. For TPS, we have neither engineering experience nor systemic study base. As one part of reusable lunch vehicle TPS researches and the beginning of systemic study in our country, the purpose of this thesis is to present a methodology to predict the transient temperature response and size TPS with high-fidelityFor RLV, the weight of the TPS is typically comparable to the payload weight. Therefore, any improvement of TPS sizing calculations, which leads to an actual reduction in TPS weight, has a significant cost and feasibility impact on RLV design. TPS design involves proper selecting and locating a great number of TPS materials, which have complex configuration and heat transfer mechanism. With these characteristics, a heat transfer methodology is introduced in the thesis. The methodology made the heat transfer analysis of TPS in two different analysis processes, which are bulky thermal protection system sizing and typical structures heat transfer. General TPS thermal model and typical structure thermal models are investigated respectively to realize the TPS sizing and meso-structure parameters design of typical structures.General TPS thermal model is studied in detail. According to general TPS thermal model function in the TPS thermal analysis, an one-dimensional transient heat transfer model is proposed on the assumption that its structure/material in TPS is homogeneous and ignores its meso-structure character. General TPS thermal model only deals with the effective properties of its structure. While, mass model for every TPS is given. Then the numerical analysis is developed using finite-difference method. Through particular formula analysis, an one-dimensional, non-linear, full implicit, transient finite-difference model is proposed. General TPS thermal model meets the requirement of analysis in extensive level and makes overall transient analysis and TPS sizingpossible.In the thesis, the TPS is described as construction of some typical structures, and TPS properties intensely depend on typical structure properties. Through comparing TPS with each other, which are widely used or have enormous potential, four typical structures are summarized, that is, rigid ceramic tile/flexible ceramic blanket, inner multiplayer insulation, metal mutil-wall structure and metal honeycomb panel. Base on investigating of heat transfer mechanism of each typical structure, heat transfer process is simplified into one or two dimensional analytical model respectively. Finite difference or finite element model is applied to different typical structure from its character. Some important parameters that influence the heat-proof properties of each typical structure are well investigated by using the numerical model, which will be helpful to direct parameter-selection and TPS properties improvement.In the last part, TPS scenario optimal design is discussed. Methodology and numerical procedure developed at this thesis is used to investigate optimum design of an envisaged two-stage-to-orbit launch vehicle thermal protection system. Under the circumference of the aerodynamic heating given by engineering, an optimal TPS material layout is proposed on the vehicle surface. Taking the vehicle as reference, optimal design of aerodynamic heating and inner structural material are examined to reduce TPS mass as possible.