Numerical Study on Combustion of Hydrogen Jet in Supersonic Airflow with Detailed and Skeletal Mechanisms

Abstract

Understanding supersonic hydrogen combustion is crucial to design propulsion systems in hypersonic vehicles. The choice of a hydrogen combustion chemical kinetics mechanism requires careful consideration of both accuracy and computational efficiency. The goal of this paper is to study the influence of this choice on the performance of the mechanisms on the problem of transverse hydrogen injection into supersonic flow with subsequent combustion taking place. The skeletal mechanism, including 7 species and 8 chemical reactions only and the detailed Kéromnès mechanism, consisting 9 species and 19 reactions are employed to quantify the effect of chemical reactions. A numerical simulation of this supersonic combustion system is performed by solving the three-dimensional Favre-averaged Navier–Stokes equations coupled with a \(k - \omega \) turbulence model. It is revealed that the basic behavior of the flowfield is mostly identical for the two mechanisms for moderate \({{M}_{\infty }}\). The notable differences are observed in the distribution of the OH mass fraction close to the wall region behind the oblique shock wave in the area of lateral flow, with a 12% increase using the detailed Kéromnès mechanism. It is found that with the growth of the \({{M}_{\infty }}\) difference increases between the results of combustion products, derived via the abridged skeletal and detailed chemical reaction mechanisms.