An energy balance equation for the three-dimensional Bödewadt and Ekman layers of the so called “BEK family" of rotating boundary-layer flows is derived. A Chebyshev discretisation method is used to solve the equations and investigate the effect of surface roughness on the physical mechanisms of transition. All roughness types lead to a stabilization of the Type I (cross-flow) instability mode for both flows, with the exception of azimuthally-anisotropic roughness (radial grooves) within the Bödewadt layer which is destabilising. In the case of the viscous Type II instability mode, the results predict a destabilisation effect of radially-anisotropic roughness (concentric grooves) on both flows, whereas both azimuthally-anisotropic roughness and isotropic roughness have a stabilisation effect. The results presented here confirm the results of our prior linear stability analyses.
|Title of host publication||Proceedings of the 16th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery|
|Publication status||Published - 2019|
|Event||16th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, ISROMAC 2016 - Honolulu, United States|
Duration: 10 Apr 2016 → 15 Apr 2016
|Conference||16th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, ISROMAC 2016|
|Period||10/04/16 → 15/04/16|
Bibliographical noteFunding Information:
This research used the ALICE High Performance Computing Facility at the University of Leicester. BA wishes to acknowledge financial support from Ministry of National Education, Republic of Turkey. SJG is supported by a Senior Research Fellowship of the Royal Academy of Engineering, funded by the Leverhulme Trust.
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- BEK family