Showing papers on "Fin (extended surface) published in 2002"
TL;DR: In this article, the authors analyzed the three-dimensional fluid flow and heat transfer in a rectangular micro-channel heat sink using water as the cooling fluid and developed a numerical code based on the finite difference method and the SIMPLE algorithm to solve the governing equations.
295 citations
TL;DR: In this paper, the authors reveal the inherent relation between the filed synergy principle and the three existing mechanisms for enhancing single phase convective heat transfer, i.e., decreasing of thermal boundary layer, increasing of flow interruption and increasing of velocity gradient near a solid wall, all lead to the reduction of intersection angle between velocity and temperature gradient.
280 citations
TL;DR: In this paper, a two-dimensional transient heat transfer model for different methods of heat dissipation is used to simulate the temperature distribution in lithium-ion batteries, and it is found that forced convection cooling can mitigate temperature rise in the battery.
271 citations
TL;DR: In this paper, the delta winglet-type vortex generators are placed with a heretofore-unused orientation for the purpose of augmenting heat transfer in fin-tube heat exchanger.
254 citations
TL;DR: In this article, an experimental study on the air-side heat transfer and pressure drop characteristics for multi-louvered fin and flat tube heat exchangers has been performed, where the inlet temperatures of the air and water for heat exchanger were 21 and 45°C, respectively.
Abstract: An experimental study on the air-side heat transfer and pressure drop characteristics for multi-louvered fin and flat tube heat exchangers has been performed. For 45 heat exchangers with different louver angles (15–29°), fin pitches (1.0, 1.2, 1.4 mm) and flow depths (16, 20, 24 mm), a series of tests were conducted for the air-side Reynolds numbers of 100–600, at a constant tube-side water flow rate of 0.32 m3/h. The inlet temperatures of the air and water for heat exchangers were 21 and 45°C, respectively. The air-side thermal performance data were analyzed using effectiveness-NTU method for cross-flow heat exchanger with both fluid unmixed conditions. The heat transfer coefficient and pressure drop data for heat exchangers with different geometrical configurations were reported in terms of Colburn j-factor and Fanning friction factor f, as functions of Reynolds number based on louver pitch. The general correlations for j and f factors are developed and compared to other correlations. The f correlation indicates that the flow depth is one of the important parameters for the pressure drop.
244 citations
Patent•
09 Aug 2002
TL;DR: In this article, a heat transfer medium having high heat transfer rate, being useful in even wider fields, simple in structure, easy to made, environmentally sound, and capable of rapidly conducting heat and preserving heat in a highly efficient manner.
Abstract: Disclosed is a heat transfer medium having high heat transfer rate, being useful in even wider fields, simple in structure, easy to made, environmentally sound, and capable of rapidly conducting heat and preserving heat in a highly efficient manner. Further disclosed are a heat transfer surface and a heat transfer element utilizing the heat transfer medium. Further disclosed are applications of the heat transfer element.
206 citations
TL;DR: In this article, the authors present an analytical and numerical study on the heat transfer characteristics of forced convection across a microchannel heat sink, and two analytical approaches are used: the porous medium model and the fin approach.
177 citations
Patent•
TSMC1
TL;DR: In this article, a multiple-gate semiconductor structure is proposed, which includes a substrate, a fin formed of a semi-conducting material that has a top surface and two sidewall surfaces.
Abstract: A multiple-gate semiconductor structure is disclosed which includes a substrate, a fin formed of a semi-conducting material that has a top surface and two sidewall surfaces. The fin is subjected to a strain of at least 0.01% and is positioned vertically on the substrate; source and drain regions formed in the semi-conducting material of the fin; a gate dielectric layer overlying the fin; and a gate electrode wrapping around the fin on the top surface and the two sidewall surfaces of the fin overlying the gate dielectric layer. A method for forming the multiple-gate semiconductor structure is further disclosed.
134 citations
TL;DR: In this paper, the effects of the heat exchanger surface treatment on the frosting/defrosting behavior in a fin-tube heat exchange was investigated experimentally, and it was found that the hydrophilic surface mainly influences the freezing behavior, while the hydophobic surface has some influence on the defrosting behaviour.
Abstract: The effects of the heat exchanger surface treatment on the frosting/defrosting behavior in a fin-tube heat exchanger are investigated experimentally. It is found that the hydrophilic surface mainly influences the frosting behavior, while the hydrophobic surface has some influence on the defrosting behavior. In view of the frosting, a surface-treated heat exchanger with either hydrophilic or hydrophobic characteristic shows little improvement in the thermal performance rather than the bare aluminum heat exchanger. The results reveal that the heat exchanger with a hydrophobic surface treatment is more effective in view of the defrosting efficiency and time. The amount of residual water on the surface-treated heat exchangers is shown to be smaller than that of the bare heat exchanger. Therefore further improvements on the performance of re-operations are expected.
133 citations
TL;DR: In this article, an empirical correlation describing the airside performance of herringbone wavy fin pattern was presented, which can describe 91% of the test data within ± 15% with a mean deviation of 6.98% while the proposed friction correlation can describe 85% of database within ±15% with an average deviation of 8.82%.
Abstract: This study presents an empirical correlation describing the airside performance of herringbone wavy fin pattern. A total of 61 samples containing approximately 570 data points are used in the regression analysis. The proposed heat transfer correlation can describe 91% of the test data within ±15% with a mean deviation of 6.98% while the proposed friction correlation can describe 85% of the database within ±15% with a mean deviation of 8.82%.
129 citations
TL;DR: In this paper, the performance of annular fin of different profiles subject to locally variable heat transfer coefficient is investigated in terms of fin efficiency as a function of the ambient and fin geometry parameters.
TL;DR: In this article, the thermal and heat transfer characteristics of lauric acid during the melting and solidification processes were determined experimentally in a vertical double pipe energy storage system, and the experimental results proved that the phase change material (PCM) melts and solidifies congruently, and it was difficult to establish the solidification proceeding at the axial distances in the PCM.
TL;DR: In this paper, an experimental study for air-side thermal-hydraulic performance of brazed aluminum heat exchangers under dehumidifying conditions has been performed, where 30 samples of louvered fin heat exchanger with different geometrical parameters were evaluated.
Abstract: An experimental study for air-side thermal-hydraulic performance of brazed aluminum heat exchangers under dehumidifying conditions has been performed. For 30 samples of louvered fin heat exchangers with different geometrical parameters, the heat transfer and pressure drop characteristics for wet surface were evaluated. The test was conducted for air-side Reynolds number in the range of 80–300 and tube-side water flow rate of 320 kg/h. The dry- and wet-bulb temperatures of the inlet air for heat exchangers were 27 and 19 °C, respectively and the inlet water temperature was 6 °C. The air-side thermal performance data for cooling and dehumidifying conditions were analyzed using effectiveness- NTU method for cross-flow heat exchanger with both fluids unmixed. The test results are reported, compared with those for the dry surface heat exchangers, in terms of sensible j factor and friction factor f , as functions of Reynolds number based on louver pitch. The correlations for j and f factors are developed within rms errors of ±16.9 and ±13.6%, respectively.
TL;DR: In this paper, an experimental study is performed using an infrared thermovision to monitor temperature distribution over a plate-fin surface inside the plate finned-tube heat exchangers.
TL;DR: In this paper, the authors evaluate the heat transfer enhancement of the micro-fin tube with R-410A as a function of mass flux, heat flux, evaporating temperature and tube diameter.
Abstract: In-tube evaporation heat transfer characteristics of R-410A were experimentally investigated and analyzed as a function of evaporating temperature, mass flux, heat flux, and tube geometry. Evaporation heat transfer coefficients and pressure drops were measured for 3.0 m long smooth and micro-fin tubes with outer diameters of 9.52 and 7.0 mm, respectively. The test matrix in the present study included measurements for evaporation over a refrigerant mass flux range of 70–211 kg/m2s, a heat flux range of 5–15 kW/m2 and an evaporating temperature range of −15 to 5. The objective of this study is to evaluate the heat transfer enhancement of the micro-fin tube with R-410A as a function of mass flux, heat flux, evaporating temperature and tube diameter.
TL;DR: In this article, high performance miniature heat pipes are developed for the cooling of high heat flux electronics using new capillary structures made of a folded copper sheet fin using electric-discharge-machining technique.
TL;DR: In this article, a numerical analysis of the problem of two-dimensional, steady, incompressible, conjugate, laminar, mixed convection with surface radiation in a vertical parallel-plate channel, provided with a flush-mounted, heat generating, discrete heat source in each wall, is presented.
TL;DR: In this paper, an experimental study was performed on compact fin-and-tube heat exchangers in wet conditions, and the authors found that the effect of inlet relative humidity on the heat transfer performance is small.
TL;DR: In this paper, the authors presented a two-dimensional analysis for the efficiency of an elliptic fin under the dry, partially wet and fully wet conditions of a range of value for axis ratios, Biot numbers, and air humidifies.
TL;DR: In this paper, a generalized correlation for flow boiling heat transfer in horizontal micro-fin tubes was developed by implementing non-dimensional parameters accounting for heat transfer enhancement over smooth tubes and physical phenomena into the basic form of a smooth tube correlation.
TL;DR: In this paper, the authors investigated the enhancement of combined natural convection, conduction, and radiation heat transfer from a 25.4 mm × 25. 4 mm discrete heat source in a 127 mm ×127 mm and 41.3 mm high enclosure, using pin-fin heat sinks.
TL;DR: In this paper, the authors show that natural and forced convection air-cooled heat sinks are not well suited for cooling the components generating the electronic components generated by electronic components.
TL;DR: In this article, a thermal design of multi-stream heat exchangers of the plate and fin type is presented, based on the use of temperature vs. enthalpy diagrams or composite curves.
Patent•
24 May 2002
TL;DR: In this article, a heat dissipating device is mounted on a fin unit such that the working fluid is cooled while passing through the supply pipe, and the pump draws working fluid from the heat exchanger via a delivery pipe.
Abstract: A heat dissipating device includes a heat dissipating fin unit, a heat dissipating fan unit, a heat exchanger, and a pump. The pump draws working fluid from the heat exchanger via a delivery pipe, and supplies the working fluid back to the heat exchanger via a supply pipe. The supply pipe is mounted on the heat dissipating fin unit such that the working fluid is cooled while passing through the supply pipe.
TL;DR: In this paper, Wang et al. presented visual observation of enlarged fin-and-tube heat exchangers with and without the presence of vortex generators, showing that vortex generators significantly increase the vortrical motions of the horseshoe vortices hitting on the tubes.
TL;DR: In this paper, the effects of gravity and electric forces on single-phase convection and pool boiling were investigated in the absence of buoyancy for space applications and it was shown that the application of an external electric field generally enhances the heat exchange between a heated wire and a liquid pool.
TL;DR: The dorsal fin of the bottlenose dolphin Tursiops truncatus is a spatially heterogeneous thermal surface and that patterns of heat flux are strongly influenced by underlying vasculature.
Abstract: The dorsal fin of the bottlenose dolphin Tursiops truncatus contains blood vessels that function either to conserve or to dissipate body heat. Prior studies have demonstrated that heat flux, measured from a single position on the dorsal fin, decreases during body cooling and diving bradycardia and increases after exercise and at the termination of the dive response. While prior studies attributed changes in heat flux to changes in the pattern of blood flow, none directly investigated the influence of vascular structures on heat flux across the dorsal fin. In this study we examined whether heat flux is higher directly over a superficial vein, compared to a position away from a vein, and investigated the temporal relationship between heart rate, respiration and heat flux. Simultaneous records of heat flux and skin temperature at three positions on the dorsal fins of 19 wild bottlenose dolphins (with the fin in air and submerged) were collected, together with heart rate and respiration. When the fin was submerged, heat flux values were highest over superficial veins, usually at the distal tip, suggesting convective delivery of heat, via blood, to the skin’s surface. Conversely, in air there was no relationship between heat flux and superficial vasculature. The mean difference in heat flux (48 W m ‐2 ) measured between the three fin positions was often equal to or greater than the heat flux that had been recorded from a single position after exercising and diving in prior studies. Tachycardia at a respiratory event was not temporally related to an increase in heat flux across the dorsal fin. This study suggests that the dorsal fin is a spatially heterogeneous thermal surface and that patterns of heat flux are strongly influenced by underlying vasculature.
TL;DR: In this article, a helium-cooled divertoron concept is proposed to achieve 10 MW/m2 peak surface heat flux with a pin fin array on the cooling channel wall and finite element analyses performed to establish temperature and stress levels in a divertor target plate.
Patent•
16 Dec 2002
TL;DR: In this article, an extra strong and durable aluminium fin alloy with enhanced corrosion resistance for brazed heat exchangers was proposed, which showed improved corrosion performance with respect to pitting corrosion, excellent high temperature sagging resistance and post braze strength.
Abstract: The invention relates to an extra strong and durable aluminium fin alloy with enhanced corrosion resistance for brazed heat exchangers. The alloy is based on recycled materials. The alloy showed improved corrosion performance with respect to pitting corrosion, excellent high temperature sagging resistance and post braze strength. By optimizing the material combination of fin, tube, header and sideplates it is possible to produce a heat exchanger with adequate corrosion performance in SWAAT.
TL;DR: In this paper, the authors presented computational results in a complex three-dimensional louver geometry, where the angled louver transitions to the flat landing and joins with the tube surface, characterized by a swept leading edge and decreasing flow area between louvers.