Research on the Optimization Design of Variable-geometry Scramjet

The integratedhypersonic vehicle performance evaluation and design-scheme selection are urgently demanded during the preliminary design stage. Therefore, developing a convenient, accurate performance evaluation method for the integrated scramjet/airframe propulsion flowpath is a very important topic to be settled. In the present paper, a performance calculation program and the optimization design platform of integrated scramjet/airframe (including the three main parts of forebody/inlet, combustor and nozzle/afterbody) are developed, with area variation, mass addition, chemistry reaction, heat loss, wall friction and variable specific heat taken into consideration. The applicability of the program is validated by experimental data. Aiming at hydrogen fueled scramjet engine with variable-geometry combustor, the integrated scramjet/airframe configuration optimization design was performed with the constant dynamic pressure trajectory between flight Mach number of 3. 0 and 10. 0. The scramjet configuration with variable-geometry combustor is optimization designed; the corresponding specific impulse and thrust are obtained for different flight mach numbers(Ma=3-10). The hydrogen-fueled scramjet specific impulse and thrust data between flight Mach 3.0-10. 0 are provided in this paper, which could be a important initial target basis for the further investigation of scramjet and scramjet - powered aircraft