航空发动机低温壳体设计需求分析与指标确定策略

航空发动机的低温壳体在使用时需要满足相应的强度、刚度指标及质量要求。对发动机低温壳体在不同应用环境下进行定量需求分析以明确设计目标。通过QFD质量功能展开工具逐层分解客户需求、定位功能和物理参数,分析功能的重要性。通过模糊数学中的最大隶属度模糊评价原理,分析多种方案的适应性,得出定量分析结果,避免以往依靠经验和类比的不确定性。对优选的概念方案进行风险分析,识别重点失效模式并采取预防措施,获得设计关注的技术指标。实例分析结果表明:采取多种数理分析方法和实用工具对需求分析、方案决策、风险预估3个方面进行的方法研究和设计实践,有利于提高低温壳体的方案设计方法的科学性,具有一定的参考价值。

Design Requirements Analysis and Indicators Determination Strategy of Aeroengine Cryogenic Shell

The cryogenic shell of an aeroengine must meet the necessary strength, stiffness and the weight. Quantitative requirement analysis of aeroengine cryogenic shell was perfromed to clear the design goals in the different engine application environment. Customer requirements were decomposed by the six-sigma design concept in the QFD quality functions tools, functions and physical parameters were positioned, and the importance of the function was analyzed. Through the fuzzy evaluation principle of the maximum membership degree in fuzzy mathematics, the adaptability of the schemes was analyzed, and the quantitative analysis results were obtained, which avoided the uncertainty of experience and analogy. Finally, the risk analysis of the optimal conceptual scheme was carried out to identify the key failure modes and take preventive measures to obtain the technical indicators of design concern. The results of case analysis show that it is helpful to improve the scientific design of the scheme of low temperature shell using a variety of mathematical analysis methods and practical tools to carry out the method research and design practice of requirement analysis, concept decision and risk estimation.