HMT_2016_1810_R1_Accepted.pdf (6.4 MB)
Hybrid LES-RANS study on square cylinder unsteady heat transfer
journal contributionposted on 2016-12-14, 11:40 authored by Xiao-Sheng (Shaun) Chen, Hao XiaHao Xia
Flow passing a heated square cylinder is investigated using a hybrid LES-RANS approach on unstructured grids at a moderate Reynolds number of 22, 050. The implicit SGS is applied for LES and two turbulence models are tested for near-wall RANS: the Spalart-Allmaras model and the SST k-! model. Both models combined with the LES present good predictions of the time- and phase-averaged velocity profiles on a 4-million-cell grid. Results of the LES-SST approach agree better with the experimental data especially at locations close to the cylinder surface and this leads to improved surface convective heat transfer compared to LES-SA. Grid convergence study shows that grid resolution in the near-wall region and on the cylinder surfaces is important in resolving the unsteady convective heat transfer. Results of velocity field and surface heat transfer from the fine grid with 8 million cells compare favourably with the experimental data and show significant improvement over that of the medium and coarse grids. Analysis of turbulent statistics is performed by means of energy spectra and anisotropy invariants of the Reynolds stress tensor. Proper orthogonal decomposition (POD) is used to identify the vortex shedding phases. It is shown that the POD based phase-averaging produces more accurate velocity profiles than the conventional pressure-signal based method.
- Aeronautical, Automotive, Chemical and Materials Engineering
- Aeronautical and Automotive Engineering
Published inInternational Journal of Heat and Mass Transfer
CitationCHEN, X. and XIA, H., 2017. Hybrid LES-RANS study on square cylinder unsteady heat transfer. International Journal of Heat and Mass Transfer, 108 pt A, pp.1237-1254.
- AM (Accepted Manuscript)
Publisher statementThis work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
NotesThis paper was accepted for publication in the journal International Journal of Heat and Mass Transfer and the definitive published version is available at http://dx.doi.org/10.1016/j.ijheatmasstransfer.2016.10.081