Effect of Radial Clearance on the Flow Between Corotating Disks in Fixed Cylindrical Enclosures
Author:
Al-Shannag Mohammad1, Herrero Joan1, Humphrey Joseph A. C.2, Giralt Francesc1
Affiliation:
1. Universitat Rovira i Virgili, Department of Chemical Engineering, 43006 Tarragona, Catalonia, Spain 2. Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904-4746
Abstract
Numerical results are obtained for the isothermal laminar flow of air between a pair of disks attached to and rotating with a hub in a fixed cylindrical enclosure. The presence of radial clearances or “gaps” between the rims of the disks and the curved enclosure wall, and the finite thickness of the disks, are considered in the calculations. The gaps allow time- and circumferentially-dependent axially-directed air flow exchanges between the contiguous inter-disk spaces. As a consequence, axisymmetric calculations of the flow, whether using boundary conditions in the gaps or extended to include the entire flow domain, fail to faithfully reproduce the experimentally measured radial variations of the mean and rms circumferential velocity components in the inter-disk space. Likewise, three-dimensional calculations using the symmetry-plane boundary condition in the gaps also fail to reproduce these variations. In contrast, computationally intensive three-dimensional calculations of the entire flow domain, including the gaps, yield results in very good agreement with the measured mean and rms velocities. These three-dimensional calculations reveal large velocity fluctuations in the gap regions accompanied by corresponding large fluctuations of the inter-disk flow, reflecting a destabilization of the structure and dynamics of the latter by the former. The axisymmetric calculations as well as those using the symmetry-plane condition in the gap are included in this study principally to elucidate their shortcomings in simulating the three-dimensional flows considered; they are not the main goal of the study. Notwithstanding, the physically approximate, full domain axisymmetric calculations yield useful qualitative results. They show that increasing gap size decreases disk surface shear and the associated disk torque coefficient, but at the cost of destabilizing the inter-disk flow. This observation is in agreement with earlier findings and is better understood as the result of the present study.
Publisher
ASME International
Subject
Mechanical Engineering
Reference12 articles.
1. Schuler, C. A., Usry, W., Weber, B., Humphrey, J. A. C., and Greif, R., 1990, “On the flow in the unobstructed space between shrouded corotating disks,” Phys. Fluids A, 2, pp. 1760–1770. 2. Abrahamson, S. D., Chiang, C., and Eaton, J. K., 1991, “Flow Structure in Head Disk Assemblies and Implications for Design,” Adv. Inf. Storage Syst., 1, pp. 7111–7132. 3. Humphrey, J. A. C., Chang, C.-J., Li, H., and Schuler, C. A., 1991, “Unobstructed and obstructed rotating disk flows: A summary review relevant to information storage systems,” Adv. Inf. Storage Syst., 1, pp. 79–110. 4. Herrero, J., Giralt, F., and Humphrey, J. A. C., 1999-a, “Influence of the geometry on the structure of the flow between a pair of corotating disks,” Phys. Fluids, 110, pp. 88–96. 5. Herrero, J., Giralt, F., and Humphrey, J. A. C., 1999-b, “Non-isothermal laminar flow and heat transfer between disks corotating in a fixed enclosure,” Int. J. Heat Mass Transf., 42, pp. 3291–3306.
Cited by
13 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献
|
|