in this paper, the effect of the brownian term in natural convection of cuo-water nanofluid inside a partially filled porous cavity, with internal heat generation has been studied. it is assumed that the viscosity and thermal conductivity of nanofluid consists of a static part and a brownian part of which is a function of temperature and the volume fraction of nanofluid. because of internal hea...

The Problem of Thermal Convection.-Electrophoresis presupposes the m ain tenance of an electric field in a conductive fluid (usually a buffer solution). The electric field dV/dx cannot be maintained without a concomitant current density J2 = u(dV/dx). In an electrophoretic column of uniform cross section, the heat generated in a unit volume per unit time will thus be: dQ/dt = Jxlla = (dV/dx)2a....

In this paper we review main results of Raleigh Bénard convection. Keywords—Convection, Turbulence Thermal convection is present everywhere. We find it in heating sauce pans, boilers, furnaces, and in the atmospheres of planets and stars. Convection is one of the most studied problem in sciences and engineering due to its enormous practical importance. Yet there are many unresolved issues in th...

Turbulent convection of fluids heated from below and cooled from above, which is known in literature as Rayleigh–Bénard convection (RBC) [1]–[2], is one of the classical problems in fluid dynamics. The most interesting examples of this process are convection in atmospheres, in oceans, on surfaces of stars. There are three main parameters characterizing fluid motion in RBC: the Rayleigh number R...

For thermal mixed-convection flows, the Nusselt number is a function of Reynolds number, Grashof number and the angle between the forcedand natural-convection directions. We consider flow over a heated cylinder for which there is no universal correlation that accurately predicts Nusselt number as a function of these parameters, especially in opposing-convection flows, where the natural convecti...

Accurate modeling of heat dissipation in pediatric intracorporeal devices is crucial in avoiding tissue and blood thermotrauma. Thermal models of new Maglev ventricular assist device (VAD) concepts for the PediaFlow VAD are developed by incorporating empirical heat transfer equations with thermal finite element analysis (FEA). The models assume three main sources of waste heat generation: coppe...

Bifurcation properties, stability behavior, dynamics, and the heat transfer of convection in a horizontal fluid layer that is driven away from thermal equilibrium by imposing a vertical temperature difference are compared with those resulting from imposing a heat current. Similarities and differences are elucidated. In particular various paradigmatic backwards bifurcating convection structures ...

This paper aims to renew interest on mixed thermal convection research and to emphasize three issues that arise from the present analysis: (i) a clear definition of the reference temperature in the Boussinesq approximation; (ii) a practical delimitation of the three convective modes, which are the forced convection (FC), mixed convection (MC) and natural (or free) convection (NC); (iii) and, fi...

We investigate a novel bursting state in inclined layer thermal convection in which convection rolls exhibit intermittent, localized, transverse bursts. With increasing temperature difference, the bursts increase in duration and number while exhibiting a characteristic wave number, magnitude, and size. We propose a mechanism which describes the duration of the observed bursting intervals and co...

An application of formal model reduction to generate a boundary condition independent compact thermal model is discussed. A new method to find a lowdimensional basis that preserves the convection coefficient as a parameter is presented. Numerical results show that the method allows the convection coefficient to change from 1 to 10 while keeping the accuracy of the reduced model to within a few ...