Effects of Magnetic Field on an Unsteady Mixed Convection Flow of Nanofluids Containing Spherical and Cylindrical Nanoparticles

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Kalidas Das ◽  
Pinaki Ranjan Duari ◽  
Prabir Kumar Kundu

The present article gives a ray of light on the effects of magnetic field on an unsteady mixed convection flow of nanofluids containing nanoparticles which are spherical and cylindrical in nature. The unsteadiness in the flow is mainly caused by time dependent stretching velocity and temperature of the sheet at the surface. The governing transportation equations are first transformed into ordinary differential equations by using similarity transformations and then solved by employing Runga–Kutta–Frelberg method with shooting technique. The influence of various parameters on velocity and temperature profiles as well as wall shear stress and the rate of mass transfer are discussed through graphs and tables. The results for regular fluid (water) from the study are in excellent agreement with the results reported in the literature.

Author(s):  
Obulesu Mopuri ◽  
Charankumar Ganteda ◽  
Bhagyashree Mahanta ◽  
Giulio Lorenzini

The main aim of this investigation is to study thermo diffusion, heat source/sink, Joule and chemical effects on heat transfer in MHD mixed convection flow and mass transfer past an infinite vertical plate with ohmic heating and viscous dissipation have been studied. We consider the mixed convection flow of an incompressible and electrically conducting viscous fluid such that x* -axis is taken along the plate in upward direction and y* -axis is normal to it. A transverse constant magnetic field is applied i.e., in the direction of y*-axis. Approximate solutions have been derived for velocity, temperature, concentration profiles, skin friction, rate of heat transfer and rate of mass transfer using perturbation technique. The obtained results are discussed with the help of graphs to observe the effect of various parameters like Grashof number (Gr), the modified Grashof number (Gm), magnetic parameter (M), Permeability parameter(K), Prandtl number (Pr), Heat Sink(Q), Radiation Parameter (F), Soret parameter (S0), Eckert number (E),Schmidt number(Sc) and Chemical reaction parameter(K0) taking two cases viz. Fluid velocity, temperature and concentration profiles are comparison with Pr=0.71(Air) and Pr =7 (Water) various parameters in cooled and heated plates. Case I: when Gr > 0 (flow on cooled plate), and Case II: Gr < 0, (flow on heated plate). Both the fluid velocity and concentration rising with the increment values of Soret parameter in the fluids Air and Water and also discussed skin friction, Nusselt number and Sherwood number in the fluid’s mercury, electrolytic solution, air and water. The novelty of this study is the consideration of simultaneous occurrence of radiation, heat absorption as well as thermo- diffusion in the magnetic field. It varies in several aspects such as non-dimensional parameters, analytical solutions, and graphical solutions, the analytic solution using the Perturbation technique, and numerical solution using Matlab software for the profile.


Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 208
Author(s):  
Sajjad Haider ◽  
Imran Syed Muhammad ◽  
Yun-Zhang Li ◽  
Faraz ◽  
Adnan Saeed Butt

The current study was devoted to explicating the impacts of heat transmission in an unsteady mixed convection flow of an upper convected Maxwell (UCM) fluid passing over a continuously stretching surface under the influence of radiation and magnetic field. Appurtenant similarity transmutations were adopted in order to express the constitutive boundary layer Equations of flow and heat transmission in non-dimensionalized form. The reduced system of partial differential Equations was solved by implementing the implicit finite difference method (IFDM). Our center of attention was to scrutinize the behavior of influential flow parameters on some significant features of flow and heat transmission, which were briefly examined, discussed, and presented in both graphical and tabular formats. Finally, a comparison was established with existing literature in limiting cases to support the present results, and a good agreement was found, corroborating our work. It was predicted that the thermal diffusion rate could be controlled by varying the Prandtl number. Moreover, a rise in radiation and magnetic field parameters reduced the skin friction coefficient and led to enhance the heat transmission rate at the surface. The outcomes of the study might have viable implementations in order to improve the quality of industrial products.


2014 ◽  
Vol 90 ◽  
pp. 238-244 ◽  
Author(s):  
Md. Shakhaoath Khan ◽  
Mohammad Wahiduzzaman ◽  
Ifsana Karim ◽  
Md. Sirajul Islam ◽  
Md. Mahmud Alam

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