Wyniki wyszukiwania - BazTech

1

Newtonian heating effect on heat absorbing unsteady MHD radiating and chemically reacting free convection flow past an oscillating vertical porous plate

Prabhakar Reddy B., Makinde O. D.

International Journal of Applied Mechanics and Engineering

|

2022

|

Vol. 27, no. 1

168--187

EN

In this article, we have discussed in detail the effect of Newtonian heating on MHD unsteady free convection boundary layer flow past an oscillating vertical porous plate embedded in a porous medium with thermal radiation, chemical reaction and heat absorption. The governing PDEs of the model together with related initial and boundary conditions have been solved numerically by the finite element method. The dimensionless velocity, temperature and concentration profiles are analyzed graphically due to the effects of key parameters in the concerned model problem. Computed results for the skin friction coefficient, Nusselt number and Sherwood number are put in tabular form. It is observed that the thermal and mass buoyancy effects support the velocity whilst a reverse effect is noticed when the strength of the magnetic field is increased. The velocity and temperature enhances with an increase in the Newtonian heating and thermal radiation whilst a reverse effect is observed with an increase in the Prandtl number and heat absorption parameter. Increasing Schmidt number and chemical reaction parameter tends to depreciate both velocity and concentration. The Newtonian heating, thermal radiation and magnetic field tends to decrease in the skin friction. The Nusselt number increases with increasing Newtonian heating and heat absorption parameters. An increase in the Schmidt number and chemical reaction rate tends to improve the Sherwood number.

2

Radiation and chemical reaction effects on unsteady MHD free convection parabolic flow past an infinite isothermal vertical plate with viscous dissipation

Reddy B. Prabhakar

International Journal of Applied Mechanics and Engineering

|

2019

|

Vol. 24, no. 2

343--358

EN

The numerical investigation of the effects of radiation and chemical reaction on an unsteady MHD free convection flow with a parabolic starting motion of an infinite isothermal vertical porous plate taking into account the viscous dissipation effect has been carried out. The fluid is considered a gray, absorbing emitting radiation but a non-scattering medium. The dimensionless governing equations for this investigation are solved numerically by applying the Ritz finite element method. Numerical results for the velocity profiles, temperature profiles and concentration profiles as well as the skin-friction are presented through graphs and tables for different values of the physical parameters involved. Results obtained show a decrease in the temperature and velocity in the boundary layer as the radiation parameter increased. The velocity increases with an increase in the thermal and mass Grashof numbers and decreases with an increase in the magnetic parameter. Further, the concentration and velocity decreases with increasing the Schmidt number and chemical reaction parameter. These findings are in very good agreement with the studies reported earlier.

3

Effects of chemical reaction on transient MHD flow with mass transfer past an impulsively fixed infinite vertical plate in the presence of thermal radiation

Reddy B. Prabhakar

International Journal of Applied Mechanics and Engineering

|

2019

|

Vol. 24, no. 4

169--182

EN

The effects of chemical reaction on a transient MHD mixed convection flow with mass transfer past an impulsively fixed infinite vertical plate under the influence of a transverse magnetic field have been presented. The medium is considered to be non-scattering and the fluid to be non-gray having emitting-absorbing and optically thick radiation limit properties. The dimensionless governing equations of the flow and mass transfer with boundary conditions are solved numerically by using the Ritz finite element method. The numerical results for the velocity, temperature and the concentration profiles as well as the skin-friction coefficient for different values of physical parameters such as the radiation parameter, magnetic parameter, Schmidt number and chemical reaction parameter have been obtained and presented through graphs and tables. It has been found that there is a fall in the temperature and velocity for both air and water as the radiation parameter is increased. An increase in the Schmidt number and chemical reaction parameter results a decrease in the concentration and velocity profiles for both air and water. Furthermore, an increase in the radiation parameter, magnetic parameter, Schmidt number and chemical reaction parameter decreases the skin-friction.