Open AccessConcordancing in ESP Class Rooms
Author(s) -
Sameh Benna,
Olfa Bayoudh
Publication year - 2014
Publication title -
journal of advances in linguistics
Language(s) - English
Resource type - Journals
ISSN - 2348-3024
DOI - 10.24297/jal.v4i3.2150
Subject(s) - rayleigh number , mechanics , physics , modulation (music) , perturbation (astronomy) , linear stability , amplitude , convection , jitter , fourier series , rayleigh scattering , mathematical analysis , control theory (sociology) , mathematics , classical mechanics , optics , acoustics , natural convection , computer science , telecommunications , quantum mechanics , instability , control (management) , artificial intelligence
The effect of time periodic body force (or g-jitter or gravity modulation) on the onset of Rayleigh-Bnard electro-convention in a micropolar fluid layer is investigated by making linear and non-linear stability analysis. The stability of the horizontal fluid layer heated from below is examined by assuming time periodic body acceleration. This normally occurs in satellites and in vehicles connected with micro gravity simulation studies. A linear and non-linear analysis is performed to show that gravity modulation can significantly affect the stability limits of the system. The linear theory is based on normal mode analysis and perturbation method. Small amplitude of modulation is used to compute the critical Rayleigh number and wave number. The shift in the critical Rayleigh number is calculated as a function of frequency of modulation. The non-linear analysis is based on the truncated Fourier series representation. The resulting non-autonomous Lorenz model is solved numerically to quantify the heat transport. It is observed that the gravity modulation leads to delayed convection and reduced heat transport.