Control of Rayleigh-Bénard Convection in a Fluid Layer with Internal Heat Generation

2018 ◽  
Vol 30 (6) ◽  
pp. 885-897 ◽  
Author(s):  
Z. Alloui ◽  
Y. Alloui ◽  
P. Vasseur
2013 ◽  
Vol 135 (10) ◽  
Author(s):  
I. K. Khalid ◽  
N. F. M. Mokhtar ◽  
N. M. Arifin

Combined effect of magnetic field and internal heat generation on the onset of Rayleigh–Bénard convection in a horizontal micropolar fluid layer is studied. The bounding surfaces of the liquids are considered to be rigid-free, rigid-rigid, and free-free with combination isothermal on the spin-vanishing boundaries. A linear stability analysis is used and the Galerkin method is employed to find the critical stability parameters numerically. The influence of various parameters on the onset of convection has been analyzed. It is shown that the presence of magnetic field always has a stability effect on the Rayleigh–Bénard convection in micropolar fluid.


2006 ◽  
Vol 13 (2) ◽  
pp. 205-222 ◽  
Author(s):  
G. V. Levina ◽  
I. A. Burylov

Abstract. A numerical approach is substantiated for searching for the large-scale alpha-like instability in thermoconvective turbulence. The main idea of the search strategy is the application of a forcing function which can have a physical interpretation. The forcing simulates the influence of small-scale helical turbulence generated in a rotating fluid with internal heat sources and is applied to naturally induced fully developed convective flows. The strategy is tested using the Rayleigh-Bénard convection in an extended horizontal layer of incompressible fluid heated from below. The most important finding is an enlargement of the typical horizontal scale of the forming helical convective structures accompanied by a cells merging, an essential increase in the kinetic energy of flows and intensification of heat transfer. The results of modeling allow explaining how the helical feedback can work providing the non-zero mean helicity generation and the mutual intensification of horizontal and vertical circulation, and demonstrate how the energy of the additional helical source can be effectively converted into the energy of intensive large-scale vortex flow.


2018 ◽  
Author(s):  
Izzati Khalidah Khalid ◽  
Nor Fadzillah Mohd Mokhtar ◽  
Zailan Siri ◽  
Zarina Bibi Ibrahim ◽  
Siti Salwa Abd Gani

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Jitender Singh

The simple shooting method is revisited in order to solve nonlinear two-point BVP numerically. The BVP of the type is considered where components of are known at one of the boundaries and components of are specified at the other boundary. The map is assumed to be smooth and satisfies the Lipschitz condition. The two-point BVP is transformed into a system of nonlinear algebraic equations in several variables which, is solved numerically using the Newton method. Unlike the one-dimensional case, the Newton method does not always have quadratic convergence in general. However, we prove that the rate of convergence of the Newton iterative scheme associated with the BVPs of present type is at least quadratic. This indeed justifies and generalizes the shooting method of Ha (2001) to the BVPs arising in the higher order nonlinear ODEs. With at least quadratic convergence of Newton's method, an explicit application in solving nonlinear Rayleigh-Bénard convection in a horizontal fluid layer heated from the below is discussed where rapid convergence in nonlinear shooting essentially plays an important role.


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