Virtual Prototype Design Of Reuable Launch Vehicle

Reusable Launch Vehicle (RLV) refers to a multifunctional spacecraft, which can be re-launched to conveniently transport payload to space. RLV can run in orbit for a long time and can also complete missions with flexibility. Because of its high value in military and civil fields, many countries have attached great importance to it and conducted out active plans to develop it. Our country has also set up the theme of earth orbit transport technology in spaceflight and aviation domain of "863" scheme, expecting to support the research of RLV.Virtual prototype technology is the fruit of the development of advanced simulation technology. As a result of the difficulty in developing RLV and its strong integrating characteristic, it is necessary to build up a virtual prototype of RLV system. The thesis aims at setting up the dynamic virtual prototype for contacting series two stages of RLV system and simulating flight at ascent stage. Before building the virtual prototype, the thesis firstly gives the mathematical model of dynamics at ascent stage. The mathematical model is composed of the following parts:1) Basic algorithm library: it covers the definition of coordinate system and Euler angles, as well as simulation algorithm library, etc.2) Air-space environment model library: it includes time system, the atmosphere model, the earth model, the moon model, and the sun model, etc.3) Motion model for ascent stage flight: it contains kinematics model, dynamic model, mass characteristic model, thrust characteristic model, aerodynamic force and moment model, etc.On the basis of mathematics model, further work has been done which contributes to designing the virtual prototype of RLV system. It makes full considerations in terms of RLV system's rationality, reusability, expansibility and convenience for substitution. What have been done is mainly about:1) Based on the mathematical model, simulation functional modules have been built up. Gravity acceleration module and atmosphere module, etc. are used to calculate environment parameters. In addition, the modules which are made to calculate relevant parameters of dynamics are also covered, for instance, aerodynamic force and moment module, mass characteristic module, calculation module of centroid motion, calculation module of attitude motion and calculation module of perturbationfor the aircraft at outer space. These modules are developed according to mathematical model and following the principle of model design specification of VPM.2) Prototype models of system have been completed. RLV consists of a lot of sub systems. The thesis firstly makes an analysis of RLV system, divides hierarchical structure of RLV prototype system, and then builds up prototype model of sub system on the foundation of the functional modules of simulation. Each sub system model accomplishes certain function. Take sub system of centroid motion for example, it is used to calculate the law of centroid motion. Combining these sub systems can attain a larger system.3) Prototype model of RLV system is finished. This Prototype model can simulate the flight of all stages. Furthermore, it properly defines Interface parameters between modules, subsystems as well as modules and subsystems so that one module can easily replace another and extend its system for realization of reusability as well as generality and meeting the needs of various simulations.The prototype has made a preliminary simulation at its ascent stage. From the results of simulation, we can conclude that this prototype can meet the demands of the coarse granularity simulation in RLV system and present reasonable outcome.