Numerical Simulation of Hydrogen Air Supersonic Coaxial Jet

Abstract

In the present study, the turbulent structure of coaxial supersonic H 2 -air jet is explored numerically by solving three dimensional RANS equations along with two equation k-e turbulence model. Grid independence of the solution is demonstrated by estimating the error distribution using Grid Convergence Index. Distributions of flow parameters in different planes are analyzed to explain the mixing and combustion characteristics of high speed coaxial jets. The flow field is seen mostly diffusive in nature and hydrogen diffusion is confined to core region of the jet. Both single step laminar finite rate chemistry and turbulent reacting calculation employing EDM combustion model are performed to find the effect of turbulencechemistry interaction in the flow field. Laminar reaction predicts higher H 2 mol fraction compared to turbulent reaction because of lower reaction rate caused by turbulence chemistry interaction. Profiles of major species and temperature match well with experimental data at different axial locations; although, the computed profiles show a narrower shape in the far field region. These results demonstrate that standard two equation class turbulence model with single step kinetics based turbulence chemistry interaction can describe H 2 -air reaction adequately in high speed flows.

Numerical Investigation on the Effect of Inflow Mach Numbers on the Combustion Characteristics of a Typical Cavity-Based Supersonic Combustor

“…In several space programs, such as the X51A, which was successfully tested by NASA, the flight lasted for 200 secs at incoming Mach 5 [1,2]. Similarly, the Indian Space Research Organization (ISRO) assessed a scramjet engine in the year 2016. e flight lasted for 5 secs for Mach 6 [3][4][5].…”

“…Since it has no moving parts, it uses the atmospheric oxygen for the combustion to occur at supersonic conditions [6][7][8]. One of the prime challenges in supersonic technology is the proper designing of the combustion chamber, which is the most crucial part of the engine [4][5][6]. e combustion process is concluded within milliseconds due to its supersonic velocity.…”