Effect of transverse fuel injection system on combustion efficiency in scramjet combustor

Abstract

Supersonic mixing layer behind the hydrogen fueled wedge shaped strut has been demonstrated by means of combined fuel injection strategy. Numerical investigation on the Effect of wall transverse fuel injection system in addition with parallel fuel injection approach have been found suitable for stable flame and combustion performance. The experimental supersonic combustor observation was performed by Waidmann et al. in German Aerospace Centre (DLR), which has been utilised in validation section to examine the accuracy and applicability of present computational work. Non-reacting and reacting both types of flow field characteristics are analysed to complete the validation. Good agreement was found in the contour plots towards oblique shock incident location moreover expansion fan behaviour at the end tip of the strut was observed. Pressure graph near the combustor walls and mid plane of the combustor were well matched with numerical observation however velocity graph was best suitable for near wake region instead of far-field region. Thus Ansys 14.0 fluent software has been chosen to compare the experimental data from the literature with numerical analysis. Two-dimensional computational combustor geometry has been taken with involving steady state, SST k-ω two equation based turbulence model analysis. Finite rate-eddy dissipation chemistry based combustion model is used to analyse the combustion process. Parallel fuel injection location is engaged at the same point and the change of wall transverse fuel injection port position have been analysed. Variations can be visualised in the numerical analysis outcome of combustion and mixing performance. The combustion efficiency plot is divided in to two section i.e. rapid change in chemical reaction in all four cases and second is gradual consumption of fuel. The outcome shows that the abrupt change in 68 mm transverse fuel injector model with 96% combustion efficiency.