DOI: 10.1615/TSFP5
A NEW DYNAMIC GGDH SUBGRID-SCALE HEAT FLUX MODEL FOR LARGE-EDDY SIMULATION OF TURBULENT THERMAL FLOWS
要約
In this research, two new dynamic tensor diffusivity subgrid-scale (SGS) heat flux (HF) models are proposed for large-eddy simulation (LES) of thermal convection. The linear and nonlinear constitutive relations for these two new modelling approaches represent the most general explicit algebraic formulations possible for the family of SGS HF models constructed using the resolved temperature gradient and SGS stress tensor. As a result, these two proposed models include a number of previous dynamic SGS HF models as special cases. In contrast to the conventional dynamic eddy thermal diffusivity SGS HF model, both proposed models admit more degrees of freedom, allow non-alignment between the SGS heat flux and negative resolved temperature gradient vectors, and therefore, provide a more realistic geometrical and physical representation for the SGS heat flux vector. To validate the proposed models, numerical simulations have been performed based on a benchmark test case of an unstably stratified horizontal channel flow.