Numerical investigation of the linear stability of a free convection boundary layer flow using a thermal disturbance with a slowly increasing frequency

Paul, M.C. and Rees, D.A.S. (2008) Numerical investigation of the linear stability of a free convection boundary layer flow using a thermal disturbance with a slowly increasing frequency. Journal of Heat Transfer, 130(12), p. 122501. (doi:10.1115/1.2976554)

Full text not currently available from Enlighten.

Publisher's URL: http://dx.doi.org/10.1115/1.2976554

Abstract

Numerical simulations are performed to investigate the linear stability of a two-dimensional incompressible free convection flow induced by a vertical semi-infinite heated flat plate. A small-amplitude local temperature disturbance with a slowly increasing frequency is introduced on the surface near to the leading edge in order to generate disturbance waves within the boundary layer. The aim is to compare the response of the thermal boundary layer with that obtained by selecting discrete disturbance frequencies. In the present study, air is considered to be the working fluid for which the value of the Prandtl number is taken to be Pr=0.7. The computational results show that the disturbance decays initially until it reaches a critical distance, which depends on the current frequency of the disturbance. Thereafter the disturbance grows, but the growth rate also depends on the effective frequency of the disturbance. Comparisons with previous work using constant disturbance frequencies are given, and it is shown that the sine-sweep technique is an effective method for analyzing the instability of convectively unstable boundary layers.

Item Type:Articles
Additional Information:To obtain this article from ASME's Online Digital Store please visit asme.org
Keywords:Boundary layers, flow instability, natural convection.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Paul, Dr Manosh
Authors: Paul, M.C., and Rees, D.A.S.
Subjects:T Technology > TJ Mechanical engineering and machinery
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Journal Name:Journal of Heat Transfer
Publisher:ASME
ISSN:0022-1481

University Staff: Request a correction | Enlighten Editors: Update this record