in this paper, convection heat transfer of al2o3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. for each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. the governing equations in steady state and axisymme...

in this paper, the temperature distribution around a moving heat source had been investigated including the phase change and non phase change . in non-phase change state, the governing equation was converted to finite difference equation by finite volume method and the equation was solved by alternating direction implicit method. this method was unconditionally stable . in phase change state, t...

using the highly recommended numerical techniques, a finite element computer code is developed to analyse the steady incompressible, laminar and turbulent flows in 2-d domains with complex geometry. the petrov-galerkin finite element formulation is adopted to avoid numerical oscillations. turbulence is modeled using the two equation k-ω model. the discretized equations are written in the form o...

in this study, the effects of strength and direction of the magnetic field on lid-driven cavity flow in the whole range of magnetic field strength variations, which already used in practice up to present (0 to 10 tesla), are studied. the governing equations, including conservative equations of momentum, continuity and magnetic field equations were solved numerically. momentum and continuity equ...

A two-dimensional, unsteady, isothermal and two-phase flow of reactant-product mixture in the air-side electrode of proton exchange membrane fuel cells (PEMFC) is studied numerically in the present study. The mixture is composed of oxygen, nitrogen, liquid water and water vapor. The governing equations are two species conservation, a single momentum equation for mobile mixture, liquid mass cons...

in oil industry, spontaneous imbibition is an important phenomenon in recovery from fractured reservoirs which can be defined as spontaneous uptake of a wetting fluid into a porous solid. spontaneous imbibition involves both cocurrent and countercurrent flows. when a matrix block is partially covered by water, oil recovery is dominated by cocurrent imbibition i.e. the production of non wetting ...

tip leakage loss introduces major part of losses of the rotor in axial gas turbines. therefore, the rotor blade tip has a considerable effect on rotor efficiency. to understand the flow physics of the rotor tip leakage, we solve the flow field for different tip platforms (passive flow control) and by considering coolant tip injection (active flow control). various blade tip configurations such ...