Numerical simulation of the interaction between shock train and combustion in three-dimensional M12-02 scramjet model

摘要

The characteristics of combustion flow fields and performance for hypersonic M12-02 scramjet were numerically simulated and analyzed. The compressible two-equation k-w SST turbulence model was employed for the turbulence model and the 9-species, 27-reaction-step hydrogen-air reaction mechanism was used as the reaction kinetics model. The numerical method was verified and a good agreement was obtained between the results of the numerical simulations and the experimental data. The results showed that shock waves from the upper and lower walls respectively crossed with each other near the central axis, forming a 'diamond' shape in the high-temperature combustion region. Compared to the conventional scramjet engine, most of the fuel reaction was in pure supersonic combustion mode for this hypersonic scramjet engine. Changes in the distribution of fuel on the upper distribution between upper and lower walls is benefit for combustion enhancement while the heat transfer in the corner of the side wall is severe and should be avoided during operation. The flame investigation showed that it cannot automatically predict the flame surface temperature in advance only based on the equivalence ratio Phi according to diffusion combustion theory. Compared to Phi = 1.0 condition, the flame surface temperature for Phi = 0. condition is higher as the complicated interaction between shock waves and combustion, which makes the local air temperature and mixing extent in flame surface is more appropriate. However, in terms of the overall engine performance, the Phi = 1.0 condition has the better combustion efficiency along the whole flow path. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.