The FORTRAN CFD code 3DINAMICS has been developed to simulate momentum, mass, and heat transfer in laminar and turbulent unsteady three-dimensional flows. The code has been successfully applied to the simulation of several engineering flows, particularly we present four different ones: lid-driven cavity, natural convection in a cubical cavity, hydrodynamics in shallow ponds and three-dimensiona...

The problem of transient natural convection in a cube-shaped cavity is investigated experimentally and numerically. The motion is driven by a sudden temperature difference applied to two opposite side walls of the vessel. The experiments are performed at a Rayleigh number of 1.66 · 10 and a Prandtl number of 1109, inside a 5 · 5 · 5cm cavity made of plexiglas, with two isothermal copper walls k...

The present research note is concerned with the transient (short time) simultaneous free convection and radiation analysis of a viscous fluid along a doubly infinite vertical isothermal flat plate. To simplify a very complicated problem, an incompressible flow field is used in the analysis. Generally, the exact numerical solution of this problem is quite lengthy. However, by considering an opti...

The effects of radiation on transient natural convection of a viscous incompressible fluid confined between vertical walls have been studied. We have considered the two different cases (i) flow due to the impulsive motion and (ii) flow due to accelerated motion of one of the walls. The governing equations are solved analytically using the Laplace transform technique. The variations of velocity ...

This work is aimed at presenting numerical predictions regarding unsteady natural convection in a rectangular cavity. The flow in the buoyancy-driven cavity of 7 : 1 aspect ratio is numerically analyzed for water (Pr = 3.77) which is exposed to hot and cold vertical plates with periodic temperatures. The results are obtained for three different variable Rayleigh numbers sets whose maximum value...

The transient MHD natural convection flow of a viscous incompressible electrically conducting fluid confined between vertical walls heated/cooled asymmetrically has been studied. We have considered two different cases (i) when one of the walls is stationary and (ii) when one of the walls starts to move impulsively. The governing equations have been solved analytically using the Laplace transfor...

Numerical analysis is presented for transient buoyancy-induced natural convection from discrete heating inside a two-dimensional rectangular enclosure filled with porous medium. The study has been made for Rayleigh numbers of 100, 1000 and 10000 with an aspect ratio of 2. The left vertical wall is heated discretely to a constant high temperature and the right wall is cooled to a constant low te...

Numerical simulations of convection induced by solvent evaporation during the drying of a polymer solution are considered. This paper focuses on the transient thermal regime occurring at the beginning of the drying and transient solutal effects are not taken into account. The onset of convection (BénardMarangoni and Rayleigh-Bénard) is studied for a large range of initial thicknesses and viscos...

Free convection occuring during the drying of plane layers of polymer solutions may be due to various mechanisms, based on buoyancy or Marangoni effect, of thermal or solutal origin. This theoretical and numerical work provides all the required tools to analyze thoroughly the problem. In this transient flow, different methods (frozen time, non-normal, nonlinear methods) are proposed to predict ...

Pool boiling on surfaces where sliding bubble mechanism plays an important role has been studied. The heat transfer phenomenon for such cases has been analysed. The model considers different mechanisms such as latent heat transfer due to microlayer evaporation, transient conduction due to thermal boundary layer reformation, natural convection and heat transfer due to the sliding bubbles. Both m...