Pool boiling heat transfer has been extensively studied over decades, but the effect of boundary heating conditions on boiling received little attention. In this work, heat transfer coefficients during pool boiling of five different refrigerants (R123, R245fa, R236fa, R134a, and R22) on the outside surface of a smooth copper tube were measured at the saturation temperature of 6.7 C; water flows...

  In this paper the numerical analysis of flow and time dependent heat transfer of micro-tube conveying nanofluid in laminar flow is investigated. In this study, convection heat transfer of nanofluid and base fluid and transient analysis for time-varying heat flux for time step of 0.0001 second are elucidated. It is observed that the pumping power of nanofluid flowing and the maximum temperatur...

In this work, a Homotopy Perturbation Solution of magnetohydrodynamic (MHD) model of boundary-layer equations for an electrically conducting Nanofluid flow bounded by an infinite parallel vertical permeable plates is to be introduced. This model is applied to study the mass and heat transfer of an unsteady nanofluid, incompressible flow with suction, internal heat generation, Hall Effect and Ch...

 The forced convection heat transfer of turbulent Al2O3-water nanofluid flow inside the grooved tubeswith the different aspect ratio of the rectangular grooves is numerically investigated. The governingequations have been solved using finite volume method (FVM) coupled with SIMPLE algorithm. It isassumed the heat flux is constant on the grooved walls. The Single-phase approach is applied for th...

In this paper a laminar flow of water on an ice layer subjected to a slip condition is considered numerically. The paper describes a parametric mathematical model to simulate the coupled heat and mass transfer events occurring in moving boundary problems associated with a quasi steady state steady flow process. The discretization technique of the elliptic governing differential equations of mas...

Recovery of both latent heat and condensate from boiler flue gas is significant for improving boiler efficiency and water conservation. The condensation experiments are carried out to investigate the simultaneous heat and mass transfer across the nanoporous ceramic membranes (NPCMs) which are treated to be hydrophilic and hydrophobic surfaces using the semicontinuous supercritical reactions. Th...

In the field of permanent magnet synchronous motors (PMSMs) cooling, turbulent kinetic energy (TKE) and dissipation (TD) are used for first time to numerically evaluate heat transfer performance axial water jackets (WJs), in order investigate influence WJ's structural parameters on water-cooled system high-power-density (HPD-PMSMs). present work, temperature distribution fluid flow pattern a 40...

The effect of pulsation on the heat transfer rates, for turbulent water stream with upstream pulsation of different amplitudes, in a double-pipe heat exchanger for both parallel and counter flows, with cold water on the shell side, was investigated. Pulsation frequencies, with using a reciprocating device, ranged up to 260 cycles per minute (up to 4.3 Hz) and 5 different displacement amplitudes...

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...

In this paper, we have tried to find a solution for quick transfer of nuclear wastes from pools of cool water to dry stores to reduce the environmental concerns and financial cost of burying atomic waste. Therefore, the rate of heat transfer from atomic waste materials to the outer surface of the container should be increased. This can be achieved by covering the bottom of the pool space with c...