Bassom, AP and Gajjar, JSB, Non-stationary cross-flow vortices in three-dimensional boundary-layer flows, Proceedings of the Royal Society of London A, 417, (1852) pp. 179-212. ISSN 1364-5021 (1988) [Refereed Article]
Copyright 1988 the Royal Society
The upper-branch neutral stability of three-dimensional disturbances imposed on a three-dimensional boundary-layer profile is considered and in particular we investigate non-stationary cross-flow vortices. The wave speed is taken to be small initially and with a disturbance structure analogous to that occurring in two-dimensional boundary-layer stability the linear and nonlinear eigenrelations are derived for profiles with more than one critical layer.
For the flow due to a rotating disc we show that linear viscous neutral modes exist for all wave angles between 10.6° and 39.6°. As the extremes of this range are approached the flow structure evolves to another, either the viscous mode of Hall (Proc. R. Soc. Lond. A 406, 93 (1986)) or the non-stationary inviscid modes considered by Stuart in Gregory et al. (Phil. Trans. R. Soc. Lond. A 248, 155 (1955)). In the former case, corresponding to wave angles of 39.6°, the waves become almost stationary and in the latter case, with wave angles of 10.6° the waves are travelling much faster with a disturbance structure based on the Rayleigh scalings. The analysis is extended to include O(1) wavespeeds and we show that as the wavespeed of the cross-flow vortex approaches the free-stream value, the corresponding disturbance amplitude increases, the growth here being slower than that for two-dimensional boundary layers.
|Item Type:||Refereed Article|
|Research Division:||Mathematical Sciences|
|Research Group:||Applied mathematics|
|Research Field:||Theoretical and applied mechanics|
|Objective Division:||Expanding Knowledge|
|Objective Group:||Expanding knowledge|
|Objective Field:||Expanding knowledge in the mathematical sciences|
|UTAS Author:||Bassom, AP (Professor Andrew Bassom)|
|Web of Science® Times Cited:||32|
|Deposited By:||Mathematics and Physics|
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