Helical Force Effects on the Onset of Küppers-Lortz Instability with Free-Free Boundaries

Marcelline Essoun, Jean B. Chabi Orou

Abstract


The rotating Rayleigh-Bénard convection in the presence of helical force is modeled by a four mode Lorenz model. This model is extended to study how this force affects the onset of Küppers-Lortz (KL) instability. We observed that when S < 3, the critical Taylor number and the critical angle for the onset of KL instability decrease as helical force intensity S increases. This influence of helical force is similar to that obtained in rotating fluid layer under periodic modulation of the rotation rate (Bhattacharjee, 1990). In the range 3 S 14.9246, the system exhibits the reentrant behavior of rolls demonstrating the constructive and destructive role of rotation in the KL instability apparition. In this case, we observed that the application of this force allows the KL instability for small values of Taylor number. In addition, it has been found that there exists a threshold (14.9246) in the magnitude of the helical force that allows suppressing the KL instability in the system for any value of Taylor number.


Full Text: PDF DOI: 10.5539/apr.v4n3p61

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.

Applied Physics Research   ISSN 1916-9639 (Print)   ISSN 1916-9647 (Online)

Copyright © Canadian Center of Science and Education

To make sure that you can receive messages from us, please add the 'ccsenet.org' domain to your e-mail 'safe list'. If you do not receive e-mail in your 'inbox', check your 'bulk mail' or 'junk mail' folders.

doaj_logo_new_120 images_120. proquest_logo_120 lockss_logo_2_120 udl_120.