Micro/nano geometries with specified wall heat flux are widely encountered in electronic cooling and micro/nano-fluidic sensors. We introduce a new technique to impose the desired (positive/negative) wall heat flux boundary condition in the DSMC simulations. This technique is based on an iterative progress on the wall temperature magnitude. It is found that the proposed iterative technique has ...

in this study, mixed convection heat transfer and local and global entropy generation in aventilated square cavity have been investigated numerically. the natural convection effect isachieved by a constant heat flux imposed at the bottom wall and cooled by injecting a coldfollow. in order to investigate the effect of port location, four different placementconfigurations of the inlet and outlet ...

A numerical approach called “SIMPLER” is used to investigate the  flow and heat transfer characteristics in a square driven cavity. The two-dimensional incompressible Navier-Stokes equations were solved and the results are depicted as contour plots of stream function, vorticity, and total pressure for Reynolds numbers from 1 to 10000. At the higher values of Reynolds number, an inviscid core re...

A numerical investigation of surface heat transfer characteristics of turbulent air flows in different parallel plate grooved channels is performed using CFD code. The results are obtained for Reynolds number ranging from 10,000 to 30,000 and for arc-shaped and rectangular grooved channels. The influence of different geometric parameters of dimples as well as the number of them and the geometri...

Theoretical and experimental investigations of forced convection heat transfer from a heated flat plate embedded in porous media with a constant heat flux had been carried out in the present work. The experimental investigation included a set of experiments carried out to study the effect of Reynolds number and heat flux on the temperature profile and local Nusselt number. The investigation cov...

this paper presents results of a numerical study of mixed convection and entropy generation of cu–water nanofluid in a square ventilating cavity at different inclination angles. except a piece of bottom wall with a uniform heat flux, all of the cavity walls are insulated. the inlet port is placed at the bottom of the left wall and the outlet port is positioned at the top of the right wall. entr...

As commercial and military aircraft engines approach higher total temperatures and increasing overall fuel-to-air ratios, there exists a potential for significant heat release to occur in the turbine if energetic species emitted from the combustor are further oxidized during interaction with film-cooling flows. Currently there is little basis for understanding the effects on aero-performance an...

We present a dynamic van der Waals theory. It is useful to study phase separation when the temperature varies in space. We show that, if heat flow is applied to liquid suspending a gas droplet at zero gravity, a convective flow occurs such that the temperature gradient within the droplet nearly vanishes. As the heat flux is increased, the droplet becomes attached to the heated wall that is wett...

Controlled nuclear fusion is the most promising candidate for being an inexhaustible, clean and intrinsically safe energy source. Research in the last 60 years has focused on the fusion reactor concept called tokamak, in which a high temperature plasma is confined using magnetic fields, producing fusion reactions. Because of turbulence, the confined plasma diffuses to the outermost region of th...

Experimental studies and numerical simulation of growth and lift-off processes of single bubbles formed on designed nucleation sites have been conducted under low-gravity conditions. Merging of multiple bubbles and lift-off processes during boiling of water in the parabola flights of KC-135 aircraft were also experimentally studied. The heating area of the flat heater surface was discretized an...