Study of turbulence-radiation interaction in hypersonic turbulent boundary layers

In the paper, we conduct direct numerical simulations (DNS) to investigate the effect of turbulence-radiation interaction (TRI) in hypersonic turbulent boundary layers, representative of the Orion crew exploration vehicle (CEV) at peak heating condition during reentry. The radiative transfer equation (RTE) is solved using the tangent slab approximation. ¹ The RTE solver is line-by-line (LBL) accurate, making use of a developed efficient spectral database ² for spectral modeling. A multi-group full-spectrum correlated-k-distribution (FSCK) method ³ is used to reduce the number of RTE evaluations while preserving LBL accuracy. A nondimensional governing parameter to measure the significance of TRI is proposed, and the DNS fields with and without radiation coupling are used to assess TRI. Both the uncoupled and coupled results show that there is no sizable interaction between turbulence and radiation at the hypersonic environment under investigation. An explanation of why the intensity of TRI in the hypersonic boundary layer is smaller than that in many combustion flows is provided.