DOI: 10.1615/ICHMT.2012.ProcSevIntSympTurbHeatTransfPal
ISBN Print: 978-1-56700-302-4
ISSN: 2377-2816
The structure of a spatially evolving three-dimensional boundary layer subjected to spanwise pressure gradient
ABSTRACT
A spatially-evolving three-dimensional boundary layer, subjected to a spanwise pressure gradient, is investigated by means of highly-resolved large-eddy simulation. The pressure gradient provokes a skewing of the velocity vector, a layer of collateral flow forming close to the wall up to the position of maximum spanwise velocity. The study has been undertaken in the context of efforts to develop and test novel hybrid LES-RANS schemes for non-equilibrium near-wall flows with an emphasis on three-dimensional near-wall straining. Results included herein illustrate some complex flow-physical features of the flow provoked by pressure-induced skewing. In addition, results of test simulations are reported that demonstrate the degree to which the fidelity of the simulation in the near-wall layer suffers from the deliberate imposition of approximate wall shear stress that does not feature the correct spectral properties. These latter results are specifically pertinent to zonal hybrid schemes in which approximate information is available, at best, about the frictional wall properties. A wide range of flowphysical properties have been studied, including wall-normal two-point correlations of velocity fluctuations and their angles, relative to wall-shear fluctuations.