EPSRC Reference: |
GR/R43570/01 |
Title: |
Improvement of predictive performance of anisotropy-resolving turbulence models in post-reattachment recovery region of separated flow using LES |
Principal Investigator: |
Leschziner, Professor M |
Other Investigators: |
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Researcher Co-Investigators: |
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Project Partners: |
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Department: |
Aeronautics |
Organisation: |
Imperial College London |
Scheme: |
Standard Research (Pre-FEC) |
Starts: |
01 January 2002 |
Ends: |
31 December 2004 |
Value (£): |
190,068
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EPSRC Research Topic Classifications: |
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EPSRC Industrial Sector Classifications: |
Aerospace, Defence and Marine |
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Related Grants: |
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Panel History: |
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Summary on Grant Application Form |
The project focuses on the question of how to improve second-moment-closure models (with implications to other anisotropy-resolving models) in respect of their ability to return correctly the rate of flow recovery following separation and reattachment. This is motivated by the observations that virtually all models which capture well the size and mean-flow structure of separated regions fail to return the correct recovery rate after reattachment. This defect is suspected to be rooted in a misrepresentation of the effects (viscous and/or inviscid) of the wall on the time/length scales of separated shear layer when it flows along the wall and interacts with the newly developing boundary layer originating at the point of reattachment. The projects consists of two major sequential and strongly linked strands, one involving Large Eddy Simulations and related statistical analysis, and the other the formulation and testing of closure corrections. First, highly-resolved Large Eddy Simulations are to be. performed for a wall jet and a separated flow past a backwards-facing step at moderate Reynolds numbers. For each geometry, one simulation would be for a stationary reattachment wall and the other for a moving, shear-free wall. This is intended to allow inviscid wall effects to be separated from viscous ones. From the data arising for both sets of simulations, and for a third separated flow for which simulations have already been performed, fields of turbulence invariants and non-dimensional time/length-scale parameters will be extracted and examined in terms of whether they can be used as distinctive indicators of the interaction between wall-effects and the reattaching shear layer, relative to the interaction with a conventional boundary layer. The behaviour of the invariants and normalised time/length-scale parameters will be used to derive functional forms of coefficients or new terms in the length-scale governing equations with the aim of securing a superior representatyion of the postreattachment recovery process.-3-
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Key Findings |
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Potential use in non-academic contexts |
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Impacts |
Description |
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Summary |
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Date Materialised |
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Sectors submitted by the Researcher |
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Project URL: |
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Further Information: |
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Organisation Website: |
http://www.imperial.ac.uk |