scholarly journals Thermal Radiation Effect on Fully Developed Natural Convection Flow in a Vertical Micro-Channel

2021 ◽  
Vol 28 (2) ◽  
pp. 20-28
Author(s):  
B. Aina
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Thermal Radiation ◽  
Temperature Jump ◽  
Velocity Slip ◽  
Convection Flow ◽  
Physical Situation ◽  
Fluid Temperature ◽  
Micro Channel ◽  
Natural Convection Flow

The effect of thermal radiation on steady fully developed natural convection flow in a vertical micro-channel is presented in this article. Effects of velocity slip and temperature jump conditions are taken into account due to their counter effects on both the volume flow rate and the rate of heat transfer. Due to the presence of thermal radiation, the momentum and energy equations are coupled system of ordinary differential equations. Governing coupled nonlinear equations are solved analytically by employing the perturbation analysis method to obtain an expression for fluid temperature, fluid velocity, rate of heat transfer and skin friction on the microchannel walls. The effect of various parameters controlling the physical situation such as thermal radiation, temperature difference, Knudsen number, and fluid wall interaction are discussed with the aid of line graphs and Tables. Results indicate that both velocity and temperature enhanced with the increase of the thermal radiation parameter. Keywords: Thermal radiation, Natural convection, Micro-channel, Velocity slip, Temperature jump

scholarly journals MHD natural convection flow of Casson fluid in an annular microchannel containing porous medium with heat generation/absorption

2020 ◽  
Vol 9 (1) ◽  
pp. 223-232 ◽  
Author(s):  
B.J. Gireesha ◽  
S. Sindhu
Keyword(s):  
Porous Medium ◽  
Natural Convection ◽  
Skin Friction ◽  
Interaction Parameter ◽  
Heat Generation ◽  
Velocity Slip ◽  
Casson Fluid ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Wall Interaction

AbstractThis study has been conducted to focus on natural convection flow of Casson fluid through an annular microchannel formed by two cylinders in the presence of magnetic field. The process of heat generation/absorption is taken into consideration. Combined effects of various parameters such as porous medium, velocity slip and temperature jump are considered. Solution of the present mathematical model is obtained numerically using fourth-fifth order Runge-Kutta-Fehlberg method. The flow velocity, thermal field, skin friction and Nusselt number are scrutinized with respect to the involved parameters of interest such as fluid wall interaction parameter, rarefaction parameter, Casson parameter and Darcy number with the aid of graphs. It is established that higher values of Casson parameter increases the skin friction coefficient. Further it is obtained that rate of heat transfer diminishes as fluid wall interaction parameter increases.

Impact of Viscous Dissipation on Fully Developed Natural Convection Flow in a Vertical Microchannel

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Basant K. Jha ◽  
Babatunde Aina
Keyword(s):  
Natural Convection ◽  
Viscous Dissipation ◽  
Velocity Slip ◽  
Coupled System ◽  
Perturbation Series ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Flow Formation ◽  
Wall Interaction ◽  
Energy Equations

In this research paper, fully developed natural convection flow in a vertical parallel plate's micro-channel in the presence of viscous dissipation is theoretically examined by using a perturbation series method. The effects of velocity slip and temperature jump are taken to consideration. Due to the presence of viscous dissipation, the momentum and energy equations are coupled system of ordinary differential equations. The influences of Knudsen number, fluid wall interaction parameter, and viscous dissipation on the flow formation and heat transfer aspects are demonstrated through graphs and tables. This result indicates that increasing the value of rarefaction parameter decreases the effect of viscous dissipation on the Nusselt number. Furthermore, it is found that the effects of rarefaction parameter as well as buoyancy parameter on temperature and velocity are significantly pronounced in the case of symmetric heating

Transient Natural Convection Between Two Zones in an Insulated Enclosure

1988 ◽  
Vol 110 (1) ◽  
pp. 116-125 ◽  
Author(s):  
P. A. Litsek ◽  
A. Bejan
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Experiments ◽  
Thermal Stratification ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Flow And Heat Transfer ◽  
Vertical Opening ◽  
The Right ◽  
Rayleigh Numbers

The natural convection flow and heat transfer between two enclosures that communicate through a vertical opening is studied by considering the evolution of an enclosed fluid in which the left half is originally at a different temperature than the right half. Numerical experiments show that at sufficiently high Rayleigh numbers the ensuing flow is oscillatory. This and other features are anticipated on the basis of scale analysis. The time scales of the oscillation, the establishment of thermal stratification, and eventual thermal equilibrium are determined and tested numerically. At sufficiently high Rayleigh numbers the heat transfer between the communicating zones is by convection, in accordance with the constant-Stanton-number trend pointed out by Jones and Otis (1986). The range covered by the numerical experiments is 102 < Ra < 107, 0.71 < Pr < 100, and 0.25 < H/L < 1.

Numerical Simulation of Natural Convection Flow in a Cube With a Horizontal Heated Strip

2008 ◽  
Author(s):  
Esam M. Alawadhi
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Nusselt Number ◽  
High Temperature ◽  
Natural Convection ◽  
Vertical Wall ◽  
Convection Flow ◽  
Front Wall ◽  
Natural Convection Flow ◽  
Rayleigh Numbers

Natural convection flow in a cube with a heated strip is solved numerically. The heated strip is attached horizontally to the front wall and maintained at high temperature, while the entire opposite wall is maintained at low temperature. The heated strip simulates an array of electronic chips The Rayleigh numbers of 104, 105, and 106 are considered in the analysis and the heated strip is horizontally attached to the wall. The results indicate that the heat transfer strongly depends on the position of the heated strip. The maximum Nusselt number can be achieved if the heater is placed at the lower half of the vertical wall. Increasing the Rayleigh number significantly promotes heat transfer in the enclosure. Flow streamlines and temperature contours are presented, and the results are validated against published works.

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