Tomsk Polytechnic University

About: Tomsk Polytechnic University is a education organization based out in Tomsk, Russia. It is known for research contribution in the topics: Combustion & Ignition system. The organization has 9190 authors who have published 13224 publications receiving 103735 citations.

Effect of thermal stratification on free convection in a square porous cavity filled with a nanofluid using Tiwari and Das' nanofluid model

Abstract: Natural convection in a square porous cavity filled with a nanofluid in conditions of thermal stratification has been numerically studied. The mathematical model has been formulated in terms of the dimensionless stream function and temperature using the Darcy–Boussinesq approximation and Tiwari and Das' nanofluid model with new more realistic empirical correlations for the physical properties of the nanofluids. Formulated partial differential equations along with the corresponding boundary conditions have been solved by the finite difference method. Particular efforts have been focused on the effects of the Rayleigh number, thermal stratification parameter, porosity of the porous medium, solid volume fraction parameter of nanoparticles, and the solid matrix of the porous medium (glass balls and aluminum foam) on the local and average Nusselt numbers, streamlines and isotherms. It has been observed an essential effect of thermal stratification parameter on heat and fluid flow fields.

Free convection in a triangular cavity filled with a porous medium saturated by a nanofluid

Abstract: Purpose – Steady-state free convection heat transfer in a right-angle triangular porous enclosure filled by a nanofluid using the mathematical nanofluid model proposed by Buongiorno has been numerically analyzed. The paper aims to discuss this issue. Design/methodology/approach – The nanofluid model takes into account the Brownian diffusion and thermophoresis effects. The governing equations formulated in terms of the vorticity-stream function variables were solved by finite difference method. Findings – It has been found that the average Nusselt number is an increasing function of the Rayleigh and Lewis numbers and a decreasing function of Brownian motion, buoyancy-ratio and thermophoresis parameters. At the same time the average Sherwood number is an increasing function of the Rayleigh and Lewis numbers, Brownian motion and thermophoresis parameters and a decreasing function of buoyancy-ratio parameter. Originality/value – The present results are new and original for the heat transfer and fluid flow in ...