• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5778-5788
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• 2015

In this study, wet surface heat transfer and friction characteristics of compound enhanced fin-and-tube heat exchangers were experimentally investigated. Louver-finned heat exchangers were also tested for comparison purpose. The effect of fin pitch on j and f factor was negligible. Both j and f factor decreased as number of tube row increased. Compound enhanced fin samples yielded higher j and f factors than louver fin samples. For one row, j and f factors of compound enhanced fin samples were 11% and 43% higher than those of louver fin samples. For two row, those were 8% and 50%, and for three row, those were 17% and 53%. Heat transfer capacities at the same pressure drop of the compound enhanced fin samples were 2.0% for one row, 3.1% for two row and 8.4% for three row larger than those of louver fin samples, Data were compared with predictions of existing louver fin correlations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3698-3707
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• 2015

In this study, wet surface heat transfer and friction characteristics of non-symmetric slit-finned heat exchangers are experimentally investigated. Louver-finned heat exchangers are also tested for comparison purpose. The effect of fin pitch on j and f factor is negligible. Louver fin samples yield higher j and f factors than slit fin samples. For one row, j and f factors of louver fin are 27% and 31% higher than those of slit fin. For two row, j and f factors of louver fin are 15% and 30% higher. Both j and f factor decrease as the number of tube row increases. For one row, average j/f ratios of slit fin samples are 3.4% larger than those of louver fin samples. For two row, average j/f ratios of slit fin samples are 11.5% larger. A new correlation was developed using the present data.

• International Journal of Air-Conditioning and Refrigeration
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• v.16 no.3
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• pp.83-88
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• 2008

A geometrically asymmetric trapezoidal fin is analyzed using the one-dimensional analytic method. Heat loss and thermal resistance are represented as a function of the fin base thickness, base height, fm shape factor, inside fluid convection characteristic number, convection characteristic numbers ratio, fm length and ambient convection characteristic number. The relationship between the fin base height and the shape factor for equal amounts of heat loss is presented. One of the results shows that the variations of the fm base thickness and the inside fluid convection characteristic number give no effect on the thermal resistance.

• Journal of Korea Foundry Society
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• v.5 no.4
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• pp.289-297
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• 1985

Thin sections in castings solidify faster than thick sections. Solidification rates increase because of an increase in heat transfer from molten meltals to molds through these solidified thin sections. The cooling fin effect in pure zinc casting was studied about the solidification time, superheat, and fin size by adopting the pourout test. The following results could be obtained from the study: (1) The fin effect could be represented by the effective cooling surface area ($A_f/S$) increased. (2) The fin effect could be obtained as functions of solidification time, superheat, and fin size.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.2
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• pp.191-197
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• 2016

In this paper, we investigated the hotcarrier injection (HCI) mechanism, one of the most important reliability issues, in 10 nm node Input/Output (I/O) bulk FinFET. The FinFET has much intensive HCI damage in Fin-bottom region, while the HCI damage for planar device has relatively uniform behavior. The local damage behavior in the FinFET is due to the geometrical characteristics. Also, the HCI is significantly affected by doping profile, which could change the worst HCI bias condition. This work suggested comprehensive understanding of HCI mechanisms and the guideline of doping profile in 10 nm node I/O bulk FinFET.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.2 no.2
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• pp.97-109
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• 1998

A comparison of the two dimensional heat loss, computed using the analytical method and the finite difference method in two models(i.e. one is a parabolic fin whose parabolic curves meet at the fin center line and the other is a transformed parabolic fin whose tip cuts vertically), is made assuming the analytical method is correct. For these methods, the root temperature and surrounding convection coefficients of these fins are assumed as constants. The results show that the relative errors of the heat loss between the two methods for the parabolic fin whose tip cuts vertically are smaller than those for the one whose tip does not cut. In case of Bi=0.01, the values of the heat loss obtained using a finite difference method are close to those values obtained using the analytical method for both models. The values of the heat loss from both models calculated by using the analytical method are almost the same for given range of non-dimensional fin length in case of Bi = 0.01 and 0.1.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.5
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• pp.511-518
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• 2000

The present experimental study investigates the impact of porous fins on the pressure drop and heat transfer characteristics in plate-fin heat exchangers. Systematic experiments have been carried out in a simplified model of a plate-porous fin heat exchanger at a controlled test environment. Comparison of performance between the porous fins and the conventional louvered fins has been made. The experimental results indicate that friction and heat transfer rate are significantly affected by permeability as well as porosity of the porous fin. The porous fins used in the present study show a similar air-side performance to the louvered fin. The correlations of friction and modified j-factor are also given for the design of the plate-porous fin heat exchanger.

• Journal of KSNVE
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• v.6 no.3
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• pp.305-315
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• 1996

Present paper aims at the correlation of modal characteristics of folding fin between test and analysis using an optimization theory. Folding fin is composed of a movable fin, a base fin, and many functional components related to the folding mechanism. Joint parts of folding fin in FEM are initially modeled as rigid elements resulting some difference between test and analysis in modal characteristics. Therefore, some equivalent springs representing joint parts are introduced to improve the FEM model. The springs were set as design variables, while the frequency difference between test and analysis was set as the object function. Bayesian procedure was ujsed for the minimization.

• Journal of the korean Society of Automotive Engineers
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• v.11 no.1
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• pp.20-30
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• 1989

The unsteady conjugate forced convection-conduction heat transfer from a plate fin is numerically studied. The external forced flow is steady but the temperature of the fin base is an exponential change with time. Therefore, the unsteady energy equations of the fluid and the fin are solved simultaneously under the conditions of equality in heat flux and temperature at the fluid-fin interface at every instant of time. Numerical results are given for various quantities of interest including the local heat transfer coefficient, the local heat flux, the total heat transfer rate and the temperature distribution of fin under the effects of the convection-conduction parameter and the ratio of thermal diffusivities. The results of the present numerical solution have been compared with those of the conventional fin theory.

• Journal of Applied Reliability
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• v.10 no.1
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• pp.65-71
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• 2010

NAND-type SONOS with a separated double-gate FinFET structure (SDF-Fin SONOS) flash memory devices are proposed to reduce the unit cell size of the memory device and increase the memory density in comparison with conventional non volatile memory devices. The proposed memory device consists of a pair of control gates separated along the direction of the Fin width. There are two unique alternative technologies in this study. One is a channel doping method and the other is an oxide thickness variation method, which are used to operate the SDF-Fin SONOS memory device as two-bit. The fabrication processes and the device characteristics are simulated by using technology comuter-adided(TCAD). The simulation results indicate that the charge trap probability depends on the different channel doping concentration and the tunneling oxide thickness. The proposed SDG-Fin SONOS memory devices hold promise for potential application.