Evaporative heat transfer coefficients of R~22 and R-407C (R-32/125/134a, 23/25/52 wt%) in a horizontal smooth tube have been measured. Heat was transferred to theJefrigerant at the test section by applying electric current directly to the stainless steel tube. Saturation temperature of refrigerant was calculated from the measured pressure. The inner wall temperatures were calculated by one dim...

Electrowetting (EW) involves the actuation of liquid droplets using electric fields and has been demonstrated as a powerful tool for initiating and controlling droplet-based microfluidic operations such as droplet transport, generation, splitting, merging and mixing. The heat transfer resulting from EWinduced droplet actuation has, however, remained largely unexplored owing to several challenge...

Recent developments in synchrotron brilliance and X-ray optics are pushing the flux density in nanofocusing experiments to unprecedented levels, which increases the risk of different types of radiation damage. The effect of X-ray induced sample heating has been investigated using time-resolved and steady-state three-dimensional finite-element modelling of representative nanostructures. Simulati...

Thermal optimization of the vertical continuous casting process is considered in the present study. The goal is to find the optimal distribution of the temperature and interfacial heat transfer coefficients corresponding to the primary and secondary cooling systems, in addition to the pulling speed, such that the solidification along the main axis of strand approaches to the unidirectional soli...

A computer model for a hot gas-fluidized bed has been developed. The theoretical description is based on a two-fluid model ( TFM) approach in which both phases are considered to be continuous and fully interpenetrating. Local wall-to-bed heattransfer coefficients have been calculated by the simultaneous solution of the TFM conservation of mass, momentum and thermal energy equations. Preliminary...

Modern computer processors require significant cooling to achieve their full performance. The “efficiency” of heat sinks is also becoming more important: cooling of electronics consumes 1% of worldwide electricity use by some estimates. Unfortunately, current cooling technologies often focus on improving heat transfer at the expense of efficiency. The present work focuses on a unique, compact, ...

a micro-channel heat exchanger reactor with different micro-baffle shapes has been studied numerically. governing equations were solved base on the finite volume method with fluent software. in upper section, oxidation reaction of methanol was occurred and in lower section, steam reforming of methanol was done. two sections were separated with solid part which played as heat exchanger and trans...

We investigate here heat transfer across interfaces consisting of single- and few-layer graphene sheets between silicon carbides by performing nonequilibrium molecular dynamics simulations. The interfacial thermal conducitivity κI is calculated by considering graphene layers as an interfacial phase. The results indicate that κI decreases with its thickness and heat flux but increases with the e...

A model for two-phase compressible flow is presented, the derivation of which is based on extended irreversible thermodynamics principles. An isentropic two-phase flow model proposed earlier and the hyperbolic model for heat transfer underlie the developed theory of this paper. The governing equations of the model form a hyperbolic system of differential equations in conservation-law form. A se...