... with a focus on the future research needs. After providing a brief introduction, the paper addresses six topics related to transport phenomena in microchannels: single-phase gas flow, enhancement in single-phase liquid flow and flow boiling, flow boiling instability, condensation, electronics cooling...

... rates. High performance microchannel heat exchangers are also attractive in applications where space and/or weight constraints dictate the size of a heat exchanger or where performance enhancement is desired. This survey article provides a historical perspective of the progress made in understanding...

...Hafiz Muhammad Ali; Adrian Briggs This paper presents a fundamental study into the underlying mechanisms influencing heat transfer during condensation on enhanced surfaces. New experimental data are reported for condensation of ethylene glycol at near atmospheric pressure and low velocity on 11...

... experimental parameters space. On the constant heat duty basis, the pumping power has been reduced up to 30% for the combined enhancement geometry than the individual enhancement geometries. A schematic diagram of the experimental setup is shown in Fig. 3 . The setup consisted of (i) a storage tank in which...

... serpentine passages with 180-deg turns under the blade tip cap. In this paper, enhanced heat transfer of a blade tip cap has been investigated numerically. The computational models consist of a two-pass channel with a 180-deg turn and various arrays of pin fins mounted on the tip cap, and a smooth two-pass...

... surface area ratios. In addition, the critical holes-to-fin surface area ratios, below which the permeable fins transfer more heat than solid fins, is found to increase as Pr and f o increase. Finally, this work paves a way for a new passive method for enhancing heat transfer. convection...

...D. Keith Hollingsworth; Larry C. Witte; Marcelino Figueroa The time-dependent temperature distribution on an inclined, thin-foil uniform-heat-generation heater was used to infer the heat transfer enhancement caused by the passage of an FC-87 bubble sliding beneath the lower surface of the heater...

...Wen-Jei Yang; Nengli Zhang; Daniel L. Vrable This paper introduces a novel heat transfer enhancement surface, referred to as metal-graphite composite surface. It is comprised of high thermal conductivity graphite microfibers interspersed within a metal matrix (copper or aluminum) to enhance...

...Mark M. Murray A convective heat transfer enhancement technique and the experimental methods used to quantify the improvement in heat transfer and subsequent differential pressure are introduced. The enhancement technique employed time varying magnetic fields produced in a pipe to cause...

... bubbles convection evaporation two-phase flow bubbles microlayers enhancement There are many convective situations where bubbles, once nucleated at an upstream position, will slide downstream along a heated surface. Cornwell and Schüller ( 1 ) found that sliding bubbles can sustain high...

... to solar irradiations. Finally, this work provides new passive methods for enhancing heat transfer in thermal systems. 15 02 2007 28 06 2007 20 05 2008 heat radiation fins irradiation heat transfer extended surfaces enhancement Heat transfer through extending...

... numbers, the existing correlations accurately reproduce the convective heat transfer and viscous pressure loss behavior in tubes. Therefore, no abnormal heat transfer enhancement was observed in this study. Viscosity of zirconia nanofluids Schematic of convective loop experimental facility...

... , 22 , pp. 541 – 550 . Alawadhi , E. M. , and Amon , C. H. , 2000 , “ Performance Analysis of an Enhanced PCM Thermal Control Unit ,” Proceedings of ITherm 2000 , Las Vegas, NV, May 24–26, pp. 283 – 289 . Baker , K. W. , Jang , J. H. , and Yu , J. S. , 1995...

...F. C. Lai; J. Mathew Prior numerical solutions of electrohydrodynamic (EHD) gas flows in a horizontal channel with a positive-corona discharged wire have revealed the existence of steady-periodic flows. It is speculated that heat transfer by forced convection may be greatly enhanced by taking...

.... For two types of three-dimensional (3D) enhanced tubes, the Turbo-CSL and the Gewa-C, the local heat flux is correlated as a function of condensation temperature difference, the film Reynolds number, the tube spacing, and liquid slinging effect. The measured heat transfer data of the plain tube were well...

...D. Gstoehl; J. R. Thome The aim of the present investigation was to study the effect of condensate inundation on the thermal performance of a vertical array of horizontal tubes with plain and enhanced surfaces. Refrigerant R-134a was condensed at a saturation temperature of 304 K on tube arrays...

...Camil-Daniel Ghiu; Yogendra K. Joshi A study of pool boiling at atmospheric pressure from single-layered enhanced structures was conducted for a dielectric fluorocarbon liquid (PF 5060). The parameters investigated in this study were: (a) Heat flux ( 1 - 45 W ∕ cm 2 ) ; (b) width...

... the surface area of the noncircular tube with that of the circular one. It has been recognized that both the local Nusselt number Nu θ and average Nusselt number N u ¯ become a function of m, Ra / Ja 1 / 4 and N σ = σ / ρ − ρ g R 2 . An enhancement in heat transfer coefficient has been observed in case...

... the view point of synergy between velocity and temperature gradient. It is shown that the synergy between velocity and temperature field becomes worse in the downstream part of the fin surface, and it is this place that enhancement technique is highly needed. The strip location of fin C just fits...

... Condensation Enhancement Finned Surfaces Heat Transfer Efforts have been deployed in recent years toward designing heat exchangers that simultaneously meet the requirements of energy saving, size reduction and subsequent cost reduction. This has led to an extensive use of heat transfer augmentation...