393 publications from this institution
In this paper magnetohydrodynamics nanofluid hydrothermal treatment in a cubic cavity heated from below is presented. The mathematical model consists of continuity and the momentum equations, while a new model is proposed to see the effects Brownian motion on the effective viscosity and thermal conductivity of nanofluid. The Lattice Boltzmann method is utilized to simulate three dimensional problems. The Koo–Kleinstreuer–Li correlation is also taken into account. Numerical calculation is made for different values of Hartmann number, nanoparticle volume fraction and Rayleigh number. The results are presented graphically in terms of streamlines, isotherms and isokinetic energy as well as Nusselt number. It is observed that the applying magnetic field results in a force opposite to the flow direction that leads to drag the flow and then reduces the convection currents by reducing the velocities. Also it can be concluded that Nusselt number is an increasing function of Rayleigh number and nanofluid volume fraction while it is a decreasing function of Hartmann number.
In this work, three dimensional flow of a fluctuating nanofluid is examined in moving (rotating) coordinates. Carbon nanotubes (multi-wall carbon nanotubes (MWCNTs)/single-wall carbon nanotubes (SWCNTs)) are taken as nanoparticles whereas water is considered as the base fluid. Xue's model for effective thermal conductivity (carbon nanotube based composite) is utilized. Entropy generation is analyzed in the presence of both homogeneous and heterogeneous mass concentrations. The dimensionless variables are introduced to obtain the dimensionless form of the boundary layer equations along with the entropy augmentation equation. Equations are then solved using an explicit scheme based on the finite differences, and the behaviour of the entropy augmentation, Bejan number and temperature is elaborated. The effects of various dimensionless parameters such as Reynolds number, Brinkman number and radiation parameter on the entropy augmentation rate, and Bejan number are presented graphically for MWCNTs and SWCNTs. Variation in the engineering coefficients (Nusselt number, skin friction, Sherwood number) are shown with various emerging parameters for MWCNTs and SWCNTs. It is found that the entropy augmentation rate can be controlled by minimizing the action of the Brinkman and Reynolds numbers. The results also reveal that the heat transfer (rate) is bigger for SWCNTs in relation to MWCNTs.
