Flow Rate Analysis and Pressure Drop Evaluation in Concentric Annular Clearances
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Abstract
Concentric annular clearances are widely used in rotating machinery, hydraulic systems, and lubrication devices. The flow rate and pressure drop in the annular clearance have a significant influence on the leakage, the load capacity, and the thermal performance of the system. In this paper, a three-dimensional model of a concentric annular clearance is established, and the internal flow field is simulated by computational fluid dynamics. The geometric configuration, axial velocity distribution, and eddy viscosity distribution are analyzed. The simulation results show that the axial velocity is highest in the central region of the clearance and decreases toward both the inner and outer walls due to the no-slip condition. A high-eddy-viscosity region appears in the core of the clearance, which indicates that the turbulent mixing is intense. A low-velocity region appears near the walls, which corresponds to the viscous sublayer. A table of key flow parameters is provided, and several governing equations are used to describe the flow behavior. The results can provide reference for the design and optimization of annular clearance systems in rotating machinery.
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References
Nakashima C Y, Oliveira Jr S, Caetano E F. Calculation of pressure drop in narrow rotating annular clearances[J]. Revista de Engenharia Térmica, 2018, 7(2).
Koivula T, Ellman A, Vilenius M. The effect of oil type on flow and cavitation properties in orifices and annular clearances[C]//Bath Workshop on Power Transmission and Motion Control (PTMC 99), University of Bath, 1999: 8–10.
Khabakhpasheva E M, Il'In Y M. Heat transfer to a melt of sodium and potassium in annular clearances[J]. The Soviet Journal of Atomic Energy, 1961, 9(6): 1038–1040.
Nakashima C Y, Oliveira Jr S D, Caetano E F. Pressure drop and heat transfer coefficients in narrow rotating annular clearances of twin-screw multiphase pumps[C]//Proceedings of the International Conference, 2005.
Beranek K, Streda I, Sestak J. On the flow of viscous liquids through annular clearances with rotating inner cylinder[J]. Acta Technica CSAV, 1979, 24(6): 665–676.
Behzad M, Alvandi M. Friction-induced backward rub of rotors in non-annular clearances: experimental observations and numerical analysis[J]. Tribology International, 2020, 152: 106430.
Guzović Z, Matijašević B, Ruševljan M. Generalized correlations for determining of heat transfer in turbine bearings and annular clearances[C]//Hrvatska znanstvena bibliografija i MZOS-Svibor, 2005.
Cole J A. Taylor vortex behaviour in annular clearances of limited length[J]. 1975.