One of the major industry problems is the flow boiling, where reaching to the critical heat flux (CHF) condition can lead to a temperature jump and damage of the systems. In the present study, the effects of a uniform change in tube diameter on subcooled flow boiling and CHF was numerically investigated. The Euler-Euler model was used to investigate the relationship between the two liquid and v...

the effect of partial slip and temperature dependent fluid properties on the mhd mixed convection flow from a heated, non-linearly stretching surface in the presence of radiation and non-uniform internal heat generation/absorption is investigated. the velocity of the stretching surface was assumed to vary according to power-law form. thermal transport is analyzed for two types of non-isothermal...

Most of the existing wall heat transfer models employed for in-cylinder flow simulations are not capable of predicting the history and peak value of the heat flux. More comprehensive models that account for density and property variations rely mainly on the standard or low-Reynolds number variants of k-ε turbulence model. Presently applied mesh resolutions already allow for first near-wall comp...

Water tunnel experiments have been performed to examine how large scale, high intensity freestream turbulence affects heat transfer through a laminar flat plate boundary layer. Time-Resolved Digital Particle Image Velocimetry (TRDPIV) was used to examine the flow field along with timeresolved heat transfer from the wall. The surface heat flux was measured with a newly developed thin-film sensor...

The present paper is an experimental investigation of roughness effects on nucleate pool boiling of refrigerant R113 on horizontal circular copper surfaces. The copper samples were treated by different sand paper grit sizes to achieve different surface roughness. The average surface roughness of the four samples was 0.901, 0.735, 0.65, and 0.09, respectively. The experiments were performed in t...

A novel algorithm has been developed for the nondestructive determination of the shape of the interface between a melt and a refractory material wall in smelter furnaces. This method uses measurements of temperature and heat flux at a number of points on the outer surface of the furnace, and assumes that the inner (guessed) surface of the furnace wall is isothermal. The temperature field is the...

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...

Heat transfer on the microand nano-scales has quickly become an important area of research and development due to its implications for use in MEMS/NEMS devices and electronics cooling [1–4] in the past decade. As these devices become more powerful with reduced volume/surface they will in turn generate more heat in a small area within a short time period, which needs to be removed as efficiently...