Three-Dimensional Simulation of Bow-Shock Instability Using Discontinuous Galerkin Method
Many experiments and numerical simulations for a bow shock that forms over a blunt body have been conducted. In general, the bow shock formed in a uniform flow is stable, and a steady bow shock can be easily obtained. However, instability of the bow shock was observed in front of nearly flat bodies in a difluorodichloromethane atmosphere, using a ballistic range 30 years ago . Baryshnikov et al. classified the features of this bow-shock instability into three types: small deformation (Fig. 1(a)), large deformation (Figs. 1(b) and (c)), and complete disruption of shock wave (Fig. 1(d)). From experiments under various conditions, it was concluded that bow-shock instability occurs depending on not only the Mach number and atmospheric pressure, but also the roundness of the edge and the curvature of the body surface. They suggested two candidates for the main mechanism of this phenomenon. One is dynamical nonequilibrium behind the shock wave due to a low specific heat ratio γ of the difluorodichloromethane; the other is chemical nonequilibrium with a quick increase in temperature at the shock front. Since direct experimental analysis of these mechanisms is difficult, numerical analysis using a sophisticated computational fluid dynamics (CFD) technique is expected to identify the mechanism that has not yet been revealed.
KeywordsShock Wave Computational Fluid Dynamic Mach Number Computational Grid Discontinuous Galerkin
Unable to display preview. Download preview PDF.
- 1.Baryshnikov, A.S., Bedin, A.P., Maslennikov, V.G., Mishin, G.I.: Stability of a bow shock. Soviet Technical Physics Letters 5, 113–114 (1979)Google Scholar
- 3.Aiso, H., Abouziarov, M., Takahashi, T.: Carbuncle instability, which does not come from the original continuous model, pp. 148–153, JAXA-SP-03-002 (2003) (in Japanese)Google Scholar
- 6.Wada, Y., Liou, M.S.: A Flux Splitting Scheme with High-Resolution and Robustness for Discontinuities. AIAA Paper 94-0083 (1994)Google Scholar
- 8.Shima, E., Kitamura, K.: On New Simple Low-Dissipation Scheme of AUSM-Family for All Speeds. AIAA paper 2009-136 (2009)Google Scholar