【作者】 高明；

【导师】 胡茑庆；

【作者基本信息】 国防科学技术大学 ， 机械工程， 2008， 硕士

【摘要】 推进剂加注系统保证了火箭发动机的推进剂供应,是发动机试验台的重要组成部分。为确保和提高其可靠性和安全性,需探寻系统的故障特征以实现准确有效的故障检测。然而加注系统的故障数据非常有限,因此在正常模型的基础上通过故障仿真的方式进行故障模式分析和研究成为可行的研究方案。本文针对液体火箭发动机加注系统,结合面向对象建模方法,应用Modelica语言和Dymola建模工具,对气、液路子系统进行了模块化建模和故障仿真的研究,主要研究内容包括:(1)详细归纳了面向对象的概念和建模方法,并对面向对象的建模工具Dymola和Modelica语言进行了概述和总结。(2)在对加注系统实际物理结构认知的基础上,应用模块化建模思想,对系统进行了合理的模块化分解。(3)分别针对气路和液路两个子系统,按照先建立数学模型再编写Modelica模型的顺序,依次构建了接口、介质、气源、贮箱、传输元件和控制元件等模块,进而构建了加注系统的两个子模块库——气路库Gas和液路库Liquid;然后依据“部件模块——子系统模型——系统模型”的步骤,从模块库中选取合适的模块逐步搭建系统模型;输入合适的参数,进行正常模型的仿真输出,并通过仿真结果与实际试验数据的对比来检验仿真精度。(4)在正常状态的模型基础上,对泄漏和堵塞两种故障模式进行了仿真,并以此总结出了故障仿真中调用模块、修改模块和设置模块参数等三种仿真方法,通过这些方法可建立故障模式仿真数据库。仿真结果表明,基于面向对象的加注系统建模与故障仿真是有效的,该技术对于后续完善推进剂加注系统故障模式库和提高液体火箭发射试验系统的安全性具有重要意义。更多还原

【Abstract】 Propellant filling system, which provides fuel and oxidant for rocket engine, is an important composition of test-bed. In order to ensure and improve its reliability and security, it is urgent to collect fault characters, which are used for accurate and effective fault detection. However, as the real fault data are very limited, it is considered that fault mode analysis based on fault simulation is a feasible research method.In this paper, the research based on object-oriented modeling method, is carried out on the moduar modeling and fault simulation of liquid rocket engine propellant filling system. The main contents of this thesis include:(1) The concept and principle of object-oriented modeling method are described in detail, and the overviews of modeling platform Dymola and language Modelica are covered.(2) Based on the understanding of real physical constitutions of filling system, the work of modular decomposition is done with the idea of modular modeling.(3) For pneumatic and hydraulic sub-system of the filling system, there build modules of real compenents including sources, medium, transport lines and otherwise in the order of first mathematic formulas and then Modelica sentences. These modules compose two model libraries-pneumatic library Gas and hydraulic library Liquid, from where we can take modules to build model of the whole filling system in terms of“parts model-sub-system model-system model”. And then parameters are set appropriately and the model is made to simulate, the simulation precision is checked after that by contrasting simulation results and real test data.(4) Based on the normal ones, models under the conditions of leak and block are simulated, during which three methods for fault simulation are summarized: adding/ detracting modules, modifying modules and setting parameters of modules. By using of these methods, data library of fault simulation can be established.The simulation results show that normal and fault simulations of the filling system based on object-oriented modeling are efficient. This method has great significance for consummating fault mode liabrary and improving the security of liquid rocket launching test.更多还原