Anisotropic unstructured mesh adaption has been introduced and used in 2-D simulations of supersonic combustion in the DLR (Deutsches Zentrum für Luft-und Raumfahrt) scramjet combustion chamber. Three cases of non-reaction flow simulation with slip wall conditions
non-reaction flow simulation with non-slip wall conditions and reaction flow simulation (with nonslip wall conditions) were carried out. In the calculations
large gradient areas with anisotropic characteristics
such as shockwaves
jet-flows
boundary layers
and flames
were detected and well refined with anisotropic meshes. As a result
compared with the initial simulation using an isotropic mesh
element numbers were reduced by 36.2%
36.4% and 36.8%
respectively
in case of slip conditions
nonslip conditions and reactions
meanwhile the accuracy and resolution in large gradient areas was even better. The results show high efficiency and high accuracy of anisotropic mesh approach compared with the isotropic mesh
for the problems with significant anisotropic characteristics such as supersonic combustion. It has been demonstrated that Hessian metrics based on Mach numbers can be used to generate anisotropic meshes for the supersonic combustion simulation.