Application of CFD and the Kriging method for optimizing the performance of a generic scramjet combustor

• Reacting flow simulations reported for DLR scramjet combustor H2 fuel.
• Optimization procedures are adopted to maximize the combustion efficiency and thrust.
• Different solutions are obtained for maximum efficiency and maximum thrust case.
• Pareto optimal chart is drawn to select the optimal point.

In this paper, the application of the Kriging method and numerical studies has been shown to optimize the position of fuel injection struts for maximizing thrust and combustion efficiency in a generic scramjet combustor. A combustor similar to DLR scramjet combustor is considered with three struts to simplify the present case for optimization studies. The studies show that a change in the position of struts results in increased pressure losses and reduced combustion efficiency scramjet combustors. Therefore, combustion efficiency and thrust have been identified as two objective functions of the present optimization study. Kriging based meta-model is applied. Complex-Box algorithm is used for global optimization. Initially, 64 simulations have been carried out for optimization studies. It has been observed that optimization results in different strut configurations for combustion efficiency and thrust and two objective functions conflict with each other. Hence, Pareto-optimal study has been carried out to obtain the best solution. 3D numerical simulations for base case, maximum thrust and maximum combustion efficiency cases confirm significant improvement for both maximum efficiency and maximum thrust cases.