Large-eddy simulation of turbulent channel flow at transcritical states

We present well-resolved large-eddy simulations (LES) of a channel flow solving the fully compressible Navier-Stokes equations in conservative form. An adaptive look-up table method is used for thermodynamic and transport properties. A physically consistent subgrid-scale turbulence model is incorporated, that is based on the Adaptive Local Deconvolution Method (ALDM) for implicit LES. The wall temperatures are set to enclose the pseudo-boiling temperature at a supercritical pressure, leading to strong property variations within the channel geometry. The hot wall at the top and the cold wall at the bottom produce asymmetric mean velocity and temperature profiles which result in different momentum and thermal boundary layer thicknesses. Different turbulent Prandtl number formulations and their components are discussed in context of strong property variations.

Automated summary

In this study, well-resolved large-eddy simulations of channel flow were conducted, solving the fully compressible Navier-Stokes equations with an adaptive look-up table method for thermodynamic and transport properties. A physically consistent subgrid-scale turbulence model based on the Adaptive Local Deconvolution Method (ALDM) was incorporated. Special treatment of wall temperatures resulted in strong property variations within the channel geometry, affecting the momentum and thermal boundary layer thicknesses. Different formulations of turbulent Prandtl number were discussed in the context of these strong property variations.