Abstract The combined thermal protection system has led the drag and heat reduction of hypersonic reentry vehicles to a new developing direction. In order to obtain better resistance to aerodynamic drag and heat while maintain the work stability of the aircraft at the same time, the optimization design of the combined thermal protection system is indispensable. In this paper, a CFD numerical simulation method is combined with a surrogate model based multi-objective optimization algorithm to optimize the configuration of a combinatorial spike and opposing jet thermal protection system in a hypersonic flow with the freestream Mach number of 5.75. The obtained results show that when the total drag coefficient (Cd) and the heat fluxes on the head of the blunt body (Q) are the objective functions, the diameter ratio of the aerodisk to the blunt body bottom (d/D) has no significant effect on the drag and heat flux reduction, and it can be neglected in the optimization process. While the objective functions Cd and Q are affected by the three variables the length-to-diameter ratio of the aerospike (L/D), the jet pressure ratio (PR), and the nozzle radius (r 0) in similar ways. Therefore, in this case, the optimization problem can be transformed into a single-objective optimization problem. The quadratic response surface model established by sample points obtained by the orthogonal experimental design method is of high simulation accuracy, with the determination coefficients of Cd and Q are 0.964 and 0.965 respectively, and there is only a difference of −6.96% in the objective function Cd, −0.93% in Q between the optimization results and the CFD results. The combined thermal protection system has better performance in both drag and heat reduction than the single spike or opposing jet systems. Compared with the pure blunt body, the total drag coefficient and heat flux on the head of the blunt body with the combined thermal protection system have significantly decreased, with the Cd goes down 86.66%, and the wall heat flux Q drops off 96.37%.
Highlights The combinational concept was optimized by surrogate-based optimization approaches. The combinational concept has better performance in both drag and heat reduction. The optimized results match well with the numerical results. All three design parameters have significant impacts on the drag and heat flux reduction.
Design exploration of combinational spike and opposing jet concept in hypersonic flows based on CFD calculation and surrogate model
Acta Astronautica ; 155 ; 287-301
2018-12-08
15 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Multiobjective Design Optimization of Hypersonic Combinational Novel Cavity and Opposing Jet Concept
Online Contents | 2017
|