Abstract：Annular cavities are found inside rotor shafts of turbomachines with an axial or radial throughflow of cooling air, which influences the thermal efficiency and system reliability of the gas turbines. The flow and heat transfer phenomena in those cavities should be investigated in order to minimize the thermal load and guarantee the system reliability. An experimental rig is set up in the Institute of Steam and Gas Turbines, RWTH Aachen University, to analyze the flow structure inside the rotating cavity with an axial throughflow of cooling air. The corresponding 3D numerical investigation is conducted with the in-house flow solver CHTflow, in which the Coriolis force and the buoyancy force are implemented in the time-dependent Navier-Stokes equations. Both the experimental and numerical results show that the whole flow structure rotating slower than the cavity rotating speed. The flow passing the observation windows in the experimental and numerical results indicates the quite similar trajectories. The computed sequences and periods of the vortex flow structure correspond closely with those observed in the experiment. Furthermore, the numerical analysis reveals a flow pattern changing between single pair, double pair, and triple pair vortices. It is suggested that the vortices inside the cavity are created by the gravitational buoyancy force in the investigated case, while the number and strength of the vortices are controlled mainly by the Coriolis force.
. How far have we been? ―Summary of investigations on rotating cavity at IDG, RWTH
Aachen University[J]. Front. Energy, 2009, 3(4): 489-497.
Dieter BOHN, Jing REN, . How far have we been? ―Summary of investigations on rotating cavity at IDG, RWTH
Aachen University. Front. Energy, 2009, 3(4): 489-497.
Sun Z, Kifoil A, Chew J, et al. Numerical simulation of natural convection instationary and rotating cavities. ASME Turob Expo 2004,Paper No. GT2004-53528, 2004
Koschmieder E L. Bénard cells and Taylor vortices. Cambridge University Press. 1993
Grossman S, Lohse D. Scaling in thermal convection:a unifying theory. J Fluid Mech, 2000, 407(1): 27―56 doi: 10.1017/S0022112099007545
Farthing P R, Long C A, Owen J M, et al. Rotating cavity with axial throughflow of coolingair: flow structure. ASME Journal of Turbomachinery, 1992, 114(1): 237―246 doi: 10.1115/1.2927991
King M, Wilson M. Free convective heat transferwithin rotating annuli. Proc 12th Int HeatTransfer Conf, Grenoble, 2002, 465―470
Owen M, Powell J. Buoyancy-induced flow ina heated rotating cavity. ASME Turob Expo 2004, Paper No.GT2004-3210, 2004
Owen J M, Wilson M. Some current research inrotating-disc systems. Book of AbstractsInt Symposium on Heat Transfer in Gas Turbine Systems, Chesme, Turkey, 2000, 35―37
Vasiliev I V. On the prediction of axisymmetric rotating flows by a one-equationturbulence moDel. ASME Journal of FluidsEngineering, 2000, 122(2): 264―272 doi: 10.1115/1.483254
Long C A, Tucker P G. Numerical computation oflaminar flow in a heated rotating cavity with an axial throughflowof air. International Journal of NumericalMethods for Heat & Fluid Flow, 1994b, 4(4): 347―365 doi: 10.1108/EUM0000000004043
Long C A, Morse A P, Tucker P G. Measurement and computation of heat transfer in highpressure compressor drum geometries with axial throughflow. ASME Journal of Turbomachinery, 1997, 119(1): 51―60
Bohn D, Deutsch G, Simon B, et al. Visualization of flow phenomena in rotatingcavities with axial throughflow and comparison with numerical results. Proceedings of PSFVIP-2, PF032, Honolulu, 1999
Bohn D, Deutsch G, Simon B, et al. Flow visualization in a rotating cavity withaxial throughflow. ASME-Paper 2000-GT-280, 2000
Bohn D, Bouzidi F, Kitanina E, et al. Numerical and experimental Investigations ofthe air flow and heat transfer in rotating cavities. The 9th International Symposium on Transport Phenomena and Dynamicsof Rotating Machinery, Honolulu, 2002
Bohn D, Ren J. Influence of laminar andturbulent viscosity on the unstable flow pattern in a rotating cavity. The 7th European Turbomachinery Conference, Athens, 2007
King M, Wilson M, Owen M. Rayleigh- Bénard convection in open and closedrotating cavities. ASME Turbo Expo 2005, Paper No. GT2005-68948, 2005
Kim SY,Han J C,mORRISON GL. Influence of surface heating condition on local heattransfer in enclosed co-rotating disks with axial through flow. ASME Paper 93–gt-258,1993,
Schmatz M A. Three-dimensional viscous flow simulations using an implicit relaxationscheme. Notes on Numerical Fluid-Mechanics(NNFM), Vieweg, Brunswick, 1988, 22: 226―242
Eberle A, Schmatz M A, Bissinger N. Generalized flux vectors for hypersonic shock-capturing. AIAA-paper 90-0390, 1990
Anderson W K, Thomas J L, van Leer B A. Comparison of finite volume flux vector splitting forthe euler equations. AIAA-Paper 85-0122, 1985
