Large Eddy Simulation Requirements for the Flow over Periodic Hills
TypeArticles dans des revues avec comité de lecture
Large eddy simulations are carried out for flows in a channel with streamwise-periodic constrictions, a well-documented benchmark case to study turbulent flow separation from a curved surface. Resolution criteria such as wall units are restricted to attached flows and enhanced criteria, such as energy spectra or two-point correlations, are used to evaluate the effective scale separation in the present large eddy simulations. A detailed analysis of the separation above the hill crest and of the early shear layer development shows that the delicate flow details in this region may be hardly resolved on coarse grids already at Re = 10595, possibly leading to a non monotonic convergence with mesh refinement. The intricate coupling between numerical and modeling errors is studied by means of various discretization schemes and subgrid models. It is shown that numerical schemes maximizing the resolution capabilities are a key ingredient for obtaining high-quality solutions while using a reduced number of grid points. On this respect, the introduction of a sharp enough filter is an essential condition for separating accurately the resolved scales from the subfilter scales and for removing ill-resolved structures. The high-resolution approach is seen to provide solutions in very good overall agreement with the available experimental data for a range of Reynolds numbers (up to 37000) without need for significant grid refinement.
Files in this item
Showing items related by title, author, creator and subject.
SCIACOVELLI, Luca; CINNELLA, Paola; GLOERFELT, Xavier (Springer, 2018)Dense gas effects, encountered in many engineering applications, lead to unconventional variations of the thermodynamic and transport properties in the supersonic flow regime, which in turn are responsible for considerable ...
GLOERFELT, Xavier; CINNELLA, Paola (American Institute of Aeronautics and Astronautics, 2015)The present study aims at getting better insight of the complex flow dynamics in a channel constricted by periodic hills. This is a popular test case ofer used to assess LES and RANS/LES models, which appears as a compendium ...
SCIACOVELLI, Lucas; CINNELLA, Paola; GLOERFELT, Xavier (Cambridge University Press (CUP), 2017)The influence of dense-gas effects on compressible wall-bounded turbulence is investigated by means of direct numerical simulations of supersonic turbulent channel flows. Results are obtained for PP11, a heavy fluorocarbon ...
Large eddy simulation of turbomachinery flows using a high-order implicit residual smoothing scheme HOARAU, Jean-Christophe; CINNELLA, Paola; GLOERFELT, Xavier (Elsevier, 2020)A recently developed fourth-order accurate implicit residual smoothing scheme (IRS4) is investigated for the large eddy simulation of turbomachinery flows, characterized by moderate to high Reynolds numbers and subject to ...
BUFI, Elio A.; CINNELLA, Paola; MERLE, Xavier; CINNELLA, Paola (ASME, 2015)The design of an efficient organic rankine cycle (ORC) expander needs to take properly into account strong real gas effects that may occur in given ranges of operating conditions, which can also be highly variable. In this ...