Extended surfaces are one of the most important approaches to increase the heat transfer rate. According to the Fourier law, the heat transfer increases by increasing the contact surface of body and fluid. In this study, the effect of heat transfer has been investigated on two sets of engineered porous fins, in which the balls with different materials are sintered together. The fluid flow throu...

We have conducted large-eddy simulations (LES) of the atmospheric boundary layer with surface heat Rux variations on a spatial scale comparable to the boundary layer depth. We first ran a simulation with a horizontally homogeneous heat flux. In general the results are similar to those of previous large-eddy simulations. The model simulates a field of convective eddies having approximately the c...

The interaction of thermal radiation with conduction and laminar natural convection in a vertical circular pin, situated at participating gas, is numerically investigated. An absorbing and emitting gas is considered, and treated to be a gray participating media. Under the idealizing of gray gas, the Rosselan4 approximation is employed to describe the radiative heat flux in the energy equation. ...

We find a simple inflationary solution in an inhomogeneous spacetime with heat flux. The heat flux obeys a causal transport equation, and counteracts the inflationary decrease of energy density. At late times, the heat flux tends to zero and the fluid approaches the equation of state p = −ρ.

in order to examine the laminar convective heat transfer of nanofluid, experiments carried out using silver-oil nanofluid in a concentric annulus with outer constant heat flux as boundary condition. silver-oil nanofluid prepared by electrical explosion of wire technique and observed no nanoparticles agglomeration during nanofluid preparation process and carried out experiments. the average size...

Surface wettability is recognized as playing an important role in pool boiling and the corresponding heat transfer curve. In this work, a systematic study of pool boiling heat transfer on smooth surfaces of varying wettability (contact angle range of 5° - 180°) has been conducted and reported. Based on numerical simulations, boiling curves are calculated and boiling dynamics in each regime are ...

This paper presents a study of the flow and thermal structures in the molten glass bath of a typical glass melting furnace with a throat but without air bubblers or electric boosting. Different separate effects on the flow structure of the glass melt are simulated, but only the glass melt is considered. The net heat flux distribution is imposed at the combustion space/glass melt interface, and ...

The present paper analyzes numerically the entropy generation induced by forced convection in a canonical configuration. The configuration itself includes two well known fluid dynamic problems: (1) an external flow (flow around a cylinder, Kármán flow); and (2) an internal flow (flow between two concentric rotating cylinders, Couette flow). In many daily engineering issues (e.g., cooling of ele...

When sufficient energy is steadily supplied to a fluid, the ensuing dynamical behavior involves many spatial and temporal scales and energy is dissipated efficiently. For instance when sufficiently strong heat is supplied against the pull of gravity to a fluid, the heat flux due to fluid flow convection exceeds the heat flux due to molecular diffusion. The average of heat flux is quantified in ...

We examine the performance of several methods to estimate meteorological 1 inputs for modelling dispersion in urban areas during convective conditions. Sensible heat 2 flux, surface friction velocity and turbulent velocities are estimated from measurements of 3 mean wind speed and the standard deviation of temperature fluctuations at a single level on a 4 tower at two suburban sites and at one ...