A unique sink orientation (USO) is an orientation of the n-dimensional cube graph (n-cube) such that every face (subcube) has a unique sink. The number of unique sink orientations is nΘ(2 n) [13]. If a cube orientation is not a USO, it contains a pseudo unique sink orientation (PUSO): an orientation of some subcube such that every proper face of it has a unique sink, but the subcube itself hasn...

the aim of this paper is to enhance thermal performance of a microchannel heat sink by using nanoencapsulated phase change material (nepcm) slurry as a cooling fluid instead of pure fluid. a threedimensional model of a circular channel using water slurry of nepcm was developed. the results show a significant reduction in the mean fluid temperature along the channel and heat sink wall temperatu...

Helical coil heat exchangers are widely used in industrial applications ranging fromcryogenic processes, air-conditioning, and nuclear reactors to waste heat recovery due totheir compact size and high heat transfer coefficient. In this kind of heat exchangers, flowand heat transfer are complicated. This paper reports a numerical investigation of theinfluence of different parameters such as coil...

Microchannels and minichannels are being considered for high heat flux applications under microgravity environment in space missions. An experimental study is undertaken to determine the effect of gravitational orientation on flow boiling characteristics of water in a set of six parallel minichannels, each 1054 m wide by 197 m deep and 63.5 mm long with a hydraulic diameter of 333 m. Three orie...

Structural information in the local electric field produced by helical charge distributions, such as dissolved DNA, is revealed in a straightforward manner employing cylindrical coordinates. Comparison of structure factors derived in terms of cylindrical and helical coordinates is made. A simple coordinate transformation serves to relate the Green function in cylindrical and helical coordinates...

the paper numerically presents laminar forced convection of a nanofluid flowing in a duct at microscale. results were compared with both analytical and experimental data and observed good concordance with previous studies available in the literature. influences of brinkman and reynolds number on thermal and hydrodynamic indexes have been investigated. for a given nanofluid, no change in efficie...

Heat dissipation is a significant challenge for threedimensional integrated circuits (3D IC) due to the lack of heat removal paths and increased power density. In this paper, a 3D IC system with an embedded microfluidic cooling heat sink (MFHS) is presented. In the proposed 3D IC system, high power tiers contain embedded MFHS and high-aspect ratio (23:1) through-silicon-vias (TSVs) routed throu...

The onset of nucleate boiling in the flow of water through a microchannel heat sink was investigated. The microchannels considered were 275 lm wide by 636 lm deep. Onset of nucleate boiling was identified with a high-speed imaging system and the heat flux at incipience was measured under various flow conditions. An analytical model was developed to predict the incipient heat flux as well as the...

The efficiency of the ideal stirling cycle assumes, that the cylinder volumes are isothermal and that the temperatures in the cylinder volumes are identical to the temperatures in the heat sink and the heat source. The efficiency is then identical to the efficiency of the Carnot cycle. However, in a real stirling machine the cylinder volumes are nearly adiabatic instead of isothermal, and the h...

The historical development of thermodynamics follows the industrial revolution in the 19 century, and the advent of heat engines. It is interesting to see how such practical considerations as the efficiency of engines can lead to abstract ideas like entropy. An idealized heat engine works by taking in a certain amount of heat QH , from a heat source (for example a coal fire), converting a porti...