Numerical investigation on the shock wave transition in a three-dimensional scramjet isolator

The Reynolds averaged Navier-Stokes (RANS) equations coupled with the renormalization group (RNG) k-e and the single-step chemical reaction mechanism have been used to evaluate the influence of the radius of the strut tip, the half-angle of the strut and the strut location relative to the combustor entrance on the combustion performance of the combustor has been discussed. At the same time, the numerical method has been validated by the available experimental shadowgraph, velocity measurements and temperature measurements in the open literature. With the increasing of the radius of the strut tip, the separation region generated due to the strong interaction between the shock wave and the boundary layer becomes broader, and accordingly, a bifurcated shock wave appears at the front of the strut, then a shock wave train. The shock waves generated at the intersectional points between the walls of the strut and the sonic lines play an important role in the generation of the separation zone, and they can improve the combustion efficiency to a certain extent. Further, the mixing process is more intensive than the chemical reaction process in the vicinity of the strut base, and the combustion efficiency increases nearly monotonically with the increasing of the horizontal distance in the range considered in the current study. When the intersectional point between the leading shock wave and the upper wall overlaps with the divergence point, the combustion efficiency at the exit of the combustor becomes the largest, and its value is nearly 96.2%.

Investigation on the effect of strut configurations and locations on the combustion performance of a typical scramjet combustor

A review of the scramjet experimental data base

Numerical investigation on geometric sensitivity and flame stabilisation mechanism in H2 fueled two-strut based scramjet combustor

Effect of a revolved wedge strut induced mixing enhancement for a hydrogen fueled scramjet combustor

Results from numerical simulations of supersonic combustion of H 2 are presented. The combustor has a single stage fuel injection parallel to the main flow from the base of a wedge. The simulations have been performed using FLUENT. Realisable k-e model has been used for modelling turbulence and single step finite rate chemistry has been used for modelling the H 2 -Air kinetics. All the numerical solutions have been obtained on grids with average value for wall γ+ less than 40. Numerically predicted profiles of static pressure, axial velocity, turbulent kinetic energy and static temperature for both non-reacting as well as reacting flows are compared with the experimental data. The RANS calculations are able to predict the mean and fluctuating quantities reasonably well in most regions of the flow field. However, the single step kinetics predicts heat release much more rapid than what was seen in the experiments. Nonetheless, the overall pressure rise in the combustor due to combustion is predicted well. Also, the k-e model is not able to predict the fluctuating quantities in the base region of the wedge where there is strong anisotropy in the presence of combustion.

V. Babu

Papers

3D numerical simulation of the supersonic combustion of H2