Large-Eddy Simulation of Heat Transfer Over a Backward-Facing Step

Direct simulation of turbulent heat transfer in swept flow over a wire in a channel

“…Vogel and Eaton [3] studied heat transfer characteristics of the flow over a backwardfacing step and found that a drop in the heat transfer coefficient occurs near flow separation and a rise occurs upstream of the flow reattachment zone. This particular variation of the heat transfer coefficient in this flow has been reported in several other studies [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Some other features of this configuration include correlation of turbulence intensity with the heat transfer coefficient near reattachment, recovery of Stanton number profile after reattachment towards equilibrium turbulent boundary layer value, correlation of r.m.s.…”

“…After reaching the peak, Nu shows an approximately linear decrease followed by a rapid decrease to a very small value in the lee-ward side of the wire. As mentioned in earlier studies of heat transfer in separated/reattaching flow [3,9,[13][14][15]25,30,35,74], such a rise in the value of Nu can be attributed to impingement of large-scale eddies on the wall in the near-reattachment region which causes an event of downwash and brings colder fluid towards the wall. The rise of Nu near the reattachment region occurs due to a rise in heat transfer.…”

Large-eddy simulation of combined forced and natural convection in a vertical plane channel

“…Since the transport of the SGS thermal energy due to unresolved turbulent motions is fundamentally different and much more complex than that due to a molecular heat conduction process, it is understood that the conventional dynamic eddy thermal diffusivity SGS HF model (DEDM-HF) as introduced by Moin et al [26] cannot correctly reflect the geometrical property of the SGS HF vector as required by the physics of turbulence, and this has been confirmed by the recent study of Abe and Suga [27]. Nevertheless, the DEDM-HF is still the most popular model in literature and has been successfully applied for predicting the mean properties of the turbulent scalar fields [28][29][30][31][32][33][34][35][36]. Here, we use a suffix ''-HF" to indicate a SGS HF model, so that the abbreviation for a SGS HF model can be differentiated from that for a SGS stress model.…”

Toward advanced subgrid models for Lattice-Boltzmann-based Large-eddy simulation: Theoretical formulations

“…Because of the intrinsic nonlinearity of turbulence dynamics, the influence of the small removed scales on the large resolved ones must be taken into account via a subgrid model. Such models have been developed within the Navier-Stokes framework for many different purposes and flow regimes, including compressible flows [3,4], heat transfer [5] and generation of noise by turbulence [6], and many modelling strategies have been proposed, including multiscale and multiresolution approaches [7,8].…”