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ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

LARGE-EDDY SIMULATION OF TURBULENT FLOW AND HEAT TRANSFER IN A RIBBED SQUARE CHANNEL FLOW

Get access (open in a dialog) DOI: 10.1615/IHTC13.p1.20
12 pages

摘要

Large-eddy simulation is used to understand the flow in a square ribbed duct representative of systems designed for internal cooling of turbine blades. The presence of ribs increases turbulence levels and enhances heat transfer. To avoid material damage caused by overheating, the heat transfer and flow field knowledge is a relevant issue. The objective of the present LES study is to solve three-dimensional Navier-Stokes equations for a compressible flow to enable simulations for which the temperature variation within the flow is very significant. This simulation allows to deal with a fully developed turbulent flow and heat transfer in a ribbed channel with high blockage ratio, which parameters are chosen to reproduce the experiments of Casarsa et al. (2003). The simulation is restricted to one pitch length and periodic conditions are applied in the streamwise direction. The unsteady compressible Navier-Stokes equations are solved with a MILES approach. The spatial discretisation method is based on the cell-centred finite volume methodology. Mean and turbulent quantities are presented, together with the heat transfer. The LES captures with accuracy the mean flow structures and compares well with experimental data and other LES results. Turbulent rms quantities also agree well with available measurements. The present LES is well predicting the distribution of heat transfer enhancement, but the Nusselt number levels are under-predicted due to an insufficiency of enthalpy gradient to maintain a constant heat flux at the walls