Design and Optimization of Two-Stage-To-Orbit Launch Vehicle with Air Turbo Rocket Propulsion
- Paper number
IAC-08.C4.5.8
- Author
Dr. Chunlin Gong, Northwestern Polytechnical University, China
- Coauthor
Prof. liangxian gu, Northwestern Polytechnical University, China
- Year
2008
- Abstract
The purpose of this research was to improve space carry capability of traditional rocket-based launch vehicle by utilizing one kind of air-breathing propulsion, Air Turbo Rocket (ATR). A two stage launch vehicle concept integrated with ATR and liquid rocket was designed, and several aspects were considered, including ATR propulsion, integral configuration of ATR and rocket, aerodynamic shape of upper stage, and trajectory. ATR based first stage and rocket based upper stage were located in series, and the oxygen and hydrogen tanks were shared by two engines. ATR accelerates the vehicle from takeoff to a speed of Mach 4.5 (about 30km). Then, first stage was separated and thrown. After that, the propulsion of vehicle makes a transition to liquid rocket. The shape of upper stage was referenced to X-34. The multi-ramp inlet of ATR was located underneath abdomen of first stage. Some analysis tools were used to determine weight and size characteristics of vehicle. CATIA was used to construct CAD model and calculate the structure weight. CFD software was used to analysis aerodynamic performance and inlet performance. Quasi-one-dimensional model with finite-rate chemistry was chosen to predict performance of ATR. 3-Dimension ascent and reentry trajectory models were constructed to predict flight performance. With several design iterations between disciplines of shape, propulsion, structure, and trajectory, the baseline configuration of vehicle was found. Based on this baseline configuration, vehicle performance sensitivities to a lot of parameters were analyzed. Some critical parameters, like transition mach number, inlet size, thrusts of two stage were chosen as variable to optimize takeoff weight of vehicle in given mission. From the results of this research, the following conclusions were made:
ATR based launch vehicle has larger launch capability than rocket based vehicle. Even structure weight of inlet and turbine considered, about 20 percent of takeoff weight can be reduced.
ATR shows excellent performance below Mach 5, whose specific impulse is about 2-4 times of liquid rocket relied on the operator mach number. As the operation mach number increase to 4.5, the specific impulse decrease rapidly. So, it’s better to make a transition to rocket before Mach 4.5.
Several parameters have important influence on takeoff weight and size of this vehicle, like thrust-to-weight ratio and transition mach number. By optimizing these parameters, It’s possible to reduce the takeoff weight by about 10 percent.
- Abstract document
- Manuscript document
(absent)