University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Effect of an axial throughflow on buoyancy-induced flow in a rotating cavity

Pitz, Diogo B. Pitz, Chew, John W. and Marxen, Olaf (2019) Effect of an axial throughflow on buoyancy-induced flow in a rotating cavity International Journal of Heat and Fluid Flow, 80, 108468. pp. 1-12.

Effect of an axial throughflow on buoyancy-induced flow in a rotating cavity.pdf - Accepted version Manuscript

Download (2MB) | Preview


In this paper large-eddy simulation is used to study buoyancy-induced flow in a rotating cavity with an axial throughflow of cooling air. This configuration is relevant in the context of secondary air systems of modern gas turbines, where cooling air is used to extract heat from compressor disks. Although global flow features of these flows are well understood, other aspects such as flow statistics, especially in terms of the disk and shroud boundary layers, have not been studied. Here, previous work for a sealed rotating cavity is extended to investigate the effect of an axial throughflow on flow statistics and heat transfer. Time- and circumferentially-averaged results reveal that the thickness of the boundary layers forming near the upstream and downstream disks is consistent with that of a laminar Ekman layer, although it is shown that the boundary layer thickness distribution along the radial direction presents greater variations than in the sealed cavity case. Instantaneous profiles of the radial and azimuthal velocities near the disks show good qualitative agreement with an Ekman-type analytical solution, especially in terms of the boundary layer thickness. The shroud heat transfer is shown to be governed by the local centrifugal acceleration and by a core temperature, which has a weak dependence on the value of the axial Reynolds number. Spectral analyses of time signals obtained at selected locations indicate that, even though the disk boundary layers behave as unsteady laminar Ekman layers, the flow inside the cavity is turbulent and highly intermittent. In comparison with a sealed cavity, cases with an axial throughflow are characterised by a broader range of frequencies, which arise from the interaction between the laminar jet and the buoyant flow inside the cavity.

Item Type: Article
Divisions : Faculty of Engineering and Physical Sciences > Mechanical Engineering Sciences
Authors :
Pitz, Diogo B. Pitz
Chew, John
Date : December 2019
Funders : CAPES foundation
DOI : 10.1016/j.ijheatfluidflow.2019.108468
Copyright Disclaimer : © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license
Uncontrolled Keywords : Rotating cavities; Buoyancy-induced flow; Axial throughflow; Large-eddy simulation
Depositing User : Clive Harris
Date Deposited : 19 Sep 2019 13:55
Last Modified : 27 Sep 2020 02:08

Actions (login required)

View Item View Item


Downloads per month over past year

Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800