Comparative studies of RANS versus large eddy simulation for fan-intake interaction
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Publication Date
2019-03-01Journal Title
Journal of Fluids Engineering, Transactions of the ASME
ISSN
0098-2202
Publisher
ASME
Volume
141
Issue
3
Type
Article
This Version
NA
Metadata
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Ma, Y., Vadlamani, N., Cui, J., & Tucker, P. (2019). Comparative studies of RANS versus large eddy simulation for fan-intake interaction. Journal of Fluids Engineering, Transactions of the ASME, 141 (3)https://doi.org/10.1115/1.4041393
Abstract
The present research applied a mixed-fidelity approach to examine the fan-intake interaction. Flow separation induced by a distortion generator (DG) is either resolved using large eddy simulation (LES) or modeled using the standard k–w model, SA model, etc. The Immersed Boundary Method with Smeared Geometry (IBMSG) is employed to represent the effect of the fan and a wide range of test cases is studied by varying the (a) height of the DG and (b) proximity of the fan to the DG. Comparisons are drawn between the LES and the RANS approaches with/without the fan effect. It is found that in the "absence of fan", the discrepancies between RANS and LES is significant within the separation and reattachment region due to the well-known limitations of the standard RANS models. "With the fan installed", the deviation between RANS and LES decreases substantially. It becomes minimal when the fan is closest to the distortion generator. It implies that with an installed fan, the inaccuracies of the turbulence model are mitigated by the strong flow acceleration at the casing due to the fan. More precisely, the mass flow redistribution due to the fan has a dominant primary effect on the final predictions and the effect of turbulence model becomes secondary, thereby suggesting that high fidelity eddy resolving simulations provide marginal improvements to the accuracy for the installed cases, particularly for the short intake-fan strategies with fan getting closer to intake lip.
Sponsorship
China Scholarship Council
Identifiers
External DOI: https://doi.org/10.1115/1.4041393
This record's URL: https://www.repository.cam.ac.uk/handle/1810/286217
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