TY - GEN
T1 - Prediction and analysis of rotor tip-clearance flows using large-eddy simulation
AU - You, Donghyun
AU - Wang, Meng
AU - Moin, Parviz
AU - Mittal, Rajat
PY - 2004
Y1 - 2004
N2 - In order to analyze the dynamics of rotor tip-clearance flow and determine the underlying mechanism for the tip-leakage cavitation, a newly developed largeeddy simulation (LES) solver which combines an immersed-boundary method with a generalized curvilinear structured grid has been employed. An analysis of the LES results has been performed to understand the mean flow field, turbulence characteristics, vortex dynamics, and pressure fluctuations in the turbomachinery cascade with tip gap. Based on thorough analysis of the flow field, a guideline for reducing viscous losses in the cascade is provided. Analyses of the energy spectra and space-time correlations of the velocity fluctuations suggest that the tip-leakage vortex is subject to pitchwise wandering motion. The largest pressure drop and most intense pressure fluctuations due to the formation of the tip-leakage vortex are found in the region where the tip-leakage vortex is strongest. The effects of tip-gap size and an end-wall groove on the tip-clearance vortical structures and on the velocity and pressure fields have been investigated to explore ways for minimizing the detrimental effects of cavitation. Attempts to investigate the vortex-rotor interaction and to enhance the LES capability for realistic rotors are also discussed.
AB - In order to analyze the dynamics of rotor tip-clearance flow and determine the underlying mechanism for the tip-leakage cavitation, a newly developed largeeddy simulation (LES) solver which combines an immersed-boundary method with a generalized curvilinear structured grid has been employed. An analysis of the LES results has been performed to understand the mean flow field, turbulence characteristics, vortex dynamics, and pressure fluctuations in the turbomachinery cascade with tip gap. Based on thorough analysis of the flow field, a guideline for reducing viscous losses in the cascade is provided. Analyses of the energy spectra and space-time correlations of the velocity fluctuations suggest that the tip-leakage vortex is subject to pitchwise wandering motion. The largest pressure drop and most intense pressure fluctuations due to the formation of the tip-leakage vortex are found in the region where the tip-leakage vortex is strongest. The effects of tip-gap size and an end-wall groove on the tip-clearance vortical structures and on the velocity and pressure fields have been investigated to explore ways for minimizing the detrimental effects of cavitation. Attempts to investigate the vortex-rotor interaction and to enhance the LES capability for realistic rotors are also discussed.
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U2 - 10.1109/dod_ugc.2004.36
DO - 10.1109/dod_ugc.2004.36
M3 - Conference contribution
AN - SCOPUS:21444450649
SN - 0769522599
SN - 9780769522593
T3 - Proceedings - Department of Defense High Performance Computing Modernization Program Users Group Conference, UGC 2004
SP - 158
EP - 165
BT - Proceedings - Users Group Conference, UGC 2004
PB - IEEE Computer Society
T2 - DoD HPCMP Users Group Conference, UGC 2004
Y2 - 7 June 2004 through 11 July 2004
ER -