Effects of Brownian Motion and Thermophoresis on the Mixed Convection of Nanofluid in a Porous Channel Including Flow Reversal

2013 ◽  
Vol 101 (1) ◽  
pp. 115-136 ◽  
Author(s):  
Meisam Habibi Matin ◽  
Behzad Ghanbari
Author(s):  
Pedro Vayssiere Brandão ◽  
Leandro Alcoforado Sphaier ◽  
Leonardo Santos de Brito Alves ◽  
Nelson Rodrigues Braga junior

1989 ◽  
Vol 111 (1) ◽  
pp. 114-120 ◽  
Author(s):  
A. S. Lavine ◽  
M. Y. Kim ◽  
C. N. Shores

An experimental investigation of opposing mixed convection in an inclined pipe has been conducted. Dye injection reveals the existence of flow reversal regions. There is an optimal tilt angle that yields maximum flow reversal length. Flow reversals are seen to cause early transition to turbulence. Temperature profiles are measured across the tube cross section near the entrance to the heated section, and show the effect of tube inclination. Temperature measurements exhibit periodic behavior in the flow reversal region under some conditions, generally characterized by low tilt angle and moderate to high Reynolds and Grashof numbers. Flow visualization indicates that this periodic behavior is due to the intermittent breakdown of the flow reversal region.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Mekonnen Shiferaw Ayano ◽  
Stephen T. Sikwila ◽  
Stanford Shateyi

Mixed convection flow through a rectangular duct with at least one of the sides of the walls of the rectangle being isothermal under the influence of transversely applied magnetic field has been analyzed numerically in this study. The governing differential equations of the problem have been transformed into a system of nondimensional differential equations and then solved numerically. The dimensionless velocity, microrotation components, and temperature profiles are displayed graphically showing the effects of various values of the parameters present in the problem. The results showed that the flow field is notably influenced by the considered parameters. It is found that increasing the aspect ratio increases flow reversal, commencement of the flow reversal is observed after some critical value, and the applied magnetic field increases the flow reversal in addition to flow retardation. The microrotation components flow in opposite direction; also it is found that one component of the microrotation will show no rotational effect around the center of the duct.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Habibis Saleh ◽  
Ishak Hashim ◽  
Sri Basriati

The present analysis is concerned with the criteria for the onset of flow reversal of the fully developed mixed convection in a vertical channel under the effect of the chemical reaction. The governing equations and the critical values of the buoyancy force are solved and calculated numerically via MAPLE. Parameter zones for the occurrence of reversed flow are presented. The exothermic chemical reaction is found to enhance the flow reversal and made flow reversal possible for symmetrical walls temperature.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Saeed Islam ◽  
Arshad Khan ◽  
Poom Kumam ◽  
Hussam Alrabaiah ◽  
Zahir Shah ◽  
...  

Abstract This work analyses thermal effect for a mixed convection flow of Maxwell nanofluid spinning motion produced by rotating and bidirectional stretching cylinder. Impacts of Joule heating and internal heat source/sink are also taken into account for current investigation. Moreover, the flow is exposed to a uniform magnetic field with convective boundary conditions. The modeled equations are converted to set of ODEs through group of similar variables and are then solved by using semi analytical technique HAM. It is observed in this study that, velocity grows up with enhancing values of Maxwell, mixed convection parameters and reduces with growing values of magnetic parameter. Temperature jumps up with increasing values of heat source, Eckert number, Brownian motion,thermophoresis parameter and jumps down with growing values of Prandtl number and heat sink. The concentration is a growing function of thermophoresis parameter and a reducing function of Brownian motion and Schmidt number.


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