Research On The Frlight Scheme Of The Sub-Orbital Vehicle

Many states have largely focused on the sub-orbital technology, which has taken lots of advantages to space shuttle and spacecraft such as the low launch cost and the short preparative time. The preliminary design scheme of sub-orbital vehicle is proposed and the general concept of skip flying is introduced in the flight scheme to accelerate the development of aerospace project in china. The concept of wavy trajectory was created in the development of hypersonic vehicle, which means that the vehicle changes its orbit or dash out aerosphere again impulsed by the lift force or the boost after the vehicle sliding reentry and repeat the wavy flight. At last, the vehicle arrives above the object. The main content is studied in this paper as follows:Firstly, the key technology of sub-orbital vehicle is preliminarily analyzed and studied. The characteristic of several typical aerodynamic configurations which include the wing body, ride wave body, lift body is analyzed and compared.The scramjet engine is used in the boost system. The key principle and operational characteristics of the scramjet are mainly introduced. The feasible control and guiding scheme of the sub-orbital vehicle are introduced finally. Secondly, the mathematic model of the different flying part in the whole wavy trajectory is established. The whole wavy trajectory includes the part of flying in upper atmosphere, reentry flying part, scramjet engine restart part and dash out the atmosphere. According to the giving initial condition defined, the trajectory of the whole wavy trajectory has been calculated and is carried on simulation analysis. The method of skip flying design is feasible by simulation analysis.Finally, the parameters of the four skip wavy flying scheme are optimized. The method of step acceleration and sequential unconstrained minimization technique are used to maximize the range of the whole skip orbit and get the optimum results. The optimized parameters are more rational than the original, which make the range of the whole skip orbit largest.