Numerical Investigation of Influence of Mesh Property in Nearfield Sonic Boom Prediction

Abstract

To investigate the influence of mesh property in nearfield sonic boom prediction, the over-pressures of several typical configurations are commutated and analyzed with an in-house Reynolds Average Navier-Stokes solver. The property of mesh alignment, mesh type and mesh distribution are analyzed based on the double cone configuration and the 69-degree Delta Wing Body configuration. The experimental data from wind tunnel are used as comparisons. The results show that the Mach cone aligned method has significant improvement to the accuracy for the prediction of sonic boom in nearfield. Both structured and un-structed mesh with a cylinder zone near the model can help to capture the distribution of the over-pressure, however, it is more convenient to use unstructured mesh when deal with complex configurations. The aspect ratio and circumferential spacing affect the captured shock wave peak value and the shapes. The accuracy of the prediction can be satisfied by carefully selecting these two factors. In the last, the summarized strategies for mesh generation are applied in the sonic boom prediction of a complex supersonic transport configuration, the Lockheed Martin 1021 to verify its practicability.