The objective of the present study was the development/testing of a novel hybrid Reynolds-averaged Navier–Stokes/large-eddy simulation methodology for predicting the flow at the compressor/combustor interface of a gas turbine engine. The coupling between the flow through the outlet guide vanes and the downstream combustor prediffuser represents the first key component of this interface. Important flow characteristics include three-dimensional turbulent outlet guide-vane wakes, end-wall boundary layers, and both favorable and adverse pressure gradient effects. There is a risk of flow separation if diffuser length and area ratio are not appropriately chosen; alternatively, a significant opportunity exists to reduce system flow losses if this risk is managed properly. Outlet guide-vane/prediffuser flow thus represents a significant modeling challenge. In the present approach to Reynolds-averaged Navier–Stokes/large-eddy simulation computational fluid dynamics, the Reynolds-averaged Navier–Stokes solver is applied to the (attached) outlet guide-vane flow and the large-eddy simulation solver to the (close to separation) prediffuser. Interfacing a large-eddy simulation prediction with an upstream Reynolds-averaged Navier–Stokes prediction introduces the problem of generating a spatially and temporally correlated unsteady velocity field for large-eddy simulation inlet conditions, which is also consistent with the time-averaged Reynolds-averaged Navier–Stokes solution. A new Reynolds-averaged Navier–Stokes/large-eddy simulation coupling procedure has been developed. Experimental data for conventional and advanced outlet guide vane/prediffuser geometries are used to assess the success of the new coupled approach. The results show that the Reynolds-averaged Navier–Stokes/large-eddy simulation approach is able to provide a good balance of predictive capability, improving prediction of velocity profiles at prediffuser exit compared to Reynolds-averaged Navier–Stokes only solution, and computational cost; it offers an attractive option for outlet guide-vane/prediffuser flow prediction.
Coupled Reynolds-Averaged Navier–Stokes/Large-Eddy Simulation for Outlet Guide Vane and Prediffuser Flows
AIAA Journal ; 53 , 3 ; 678-691
2014-09-24
14 pages
Article (Journal)
Electronic Resource
English
Hybrid Large-Eddy-Reynolds-Averaged Navier -- Stokes Simulations of Shock-Separated Flows
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