• 설비공학논문집
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• 제14권12호
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• pp.1023-1030
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• 2002

This paper is to research the heat transfer characteristic performance of the copper-water heat pipe with the screen wicks. Recently, the semiconductor capacity of an electronic unit has been larger, on the contrary, its size has been much smaller. As a result, a high-performance cooling system is needed. Experimental variables are inclination angles, temperatures of cooling water and the mesh number of screen wicks. The distilled water was used for the working fluid. At the inclination angle $6^{\circ}$ in top heat mode, the two layers of the 100-mesh screen wick showed the best heat transfer performance. The thermal resistance of the two layers with the 100-mesh screen was 0.7~$0.8^{\circ}C$/W.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.187-190
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• 2014

An experimental study on downwardly and upwardly spreading flames over slanted electrical wire, which is insulated by Polyethylene(PE), was conducted with applied AC electric field. The result showed that downwardly and upwardly spreading flames with angle of inclination leaned toward burnt side and unburned side, respectively. With applied AC electric fields, size of downwardly spreading flame decreased slightly and that of upwardly spreading flame increased significantly. Flame spread rate showed various trends in terms of inclination, applied voltage and frequency.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.363-365
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• 2014

An experimental study on effect of AC electric field on upwardly spreading flame over electrical wire, which is insulated by Polyethylene(PE), was conducted. The result showed that upwardly spreading flame leaned toward unburned side with angle of inclination. With applied electric field, size of upwardly spreading flame increased significantly. Flame spread rate showed various trends with inclination, applied voltage and frequency.

• 수산해양기술연구
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• 제44권2호
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• pp.120-128
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• 2008

Estimation of the gear shape and cross section of sweep at mouth of a bottom trawl net was described and applied to the field experiments obtained with the Scanmar system. The shape of the trawl net from wingend to the beginning of codend was assumed to be part of an elliptic cone of which the cross section was ellipse, and that of the float rope be of form $y_f=a_fx^{bf}$. In case of a bottom trawl with warp 180m long, the radius of ellipse, the cross section of sweep at mouth, the eccentricity of the ellipse, the inclination angle of float rope and the contribution of the side panel to net height were estimated in accordance with towing speed. The horizontal radius of the upper ellipse increased with increasing towing speed, the eccentricity of it became slightly bigger as increasing the towing speed which meant the shape of it being flat. And the inclination angle of the float rope was about between 7 and 12 degrees in case of the above bottom trawl.

• Geomechanics and Engineering
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• 제17권3호
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• pp.279-285
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• 2019

The process of slope stability analysis is one of the most important stages in design of some civil and mining projects. Bimslopes are made from bimrocks (block-in-matrix rocks) where rocky blocks are distributed in a bonded matrix of finer texture. These kind of slopes are often seen in weathered and near-surface depths. Previous studies have shown that VBP (Volumetric Block Proportion) is one of the most significant factors affecting bimrocks strength and consequently the stability of bimslopes. In this paper, the influence of block inclinations on bimslope stability have been investigated. For this purpose, 180 theoretical models have been made with various VBPs, all of them have a specified block size distribution. These bimslopes contain blocks with differing dips relative the slope inclination. Also for each kind of block inclination, 10 different blocks arrangements have been modeled. The Finite Element Method (FEM) was used to analysis the stability of these bimslopes models. The results showed the inclination of blocks has a strong impact on the Safety Factor and stability of bimslopes. When the difference in angle of dip of blocks relative to the slope angle is maximum, the Safety Factor of bimslopes tends to be a maximum compared with the matrix-only state. Furthermore, with increasing VBP of bimslopes stability increases. The graphs obtained from this study could be used for preliminary guidance in the projects design with bimslopes.

• 한국연소학회지
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• 제19권4호
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• pp.1-7
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• 2014

An experimental study on downwardly spreading flame over slanted electrical wire, which is insulated by Polyethylene (PE), was conducted with applied AC electric fields. The result showed that the flame spread rate decreased initially with increase in inclination angle of wire and then became nearly constant. The flame shape was modified significantly with applied AC electric field due to the effect of ionic wind. Such a variation in flame spread rate could be explained by a thermal balance mechanism, depending on flame shape and slanted direction of flame. Extinction of the spreading flame was not related to angle of inclination, and was described well by a functional dependency upon the frequency and voltage at extinction.

• 설비공학논문집
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• 제9권4호
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• pp.435-445
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• 1997

It was studied the phenomena of transient freezing of an inclined water-saturated enclosure. One side of the test section was cooled and the other sides were insulated. The effects of the initial temperature, the inclination angle on the temperature field and the shape of the ice-water interface were observed. In the beginning of freezing, with increasing the inclination angle the freezing rate was increased and in the stable density layer centered $4^{\circ}C$, the freezing was fast as the convective fluid flow became small. When the initial temperature was above the $4^{\circ}C$, the frozen thickness in the upper part of inclined surface was thinner than that in the lower part, but with time the frozen thickness of upper part was thicker than that of lower part, below the $4^{\circ}C$, the frozen thickness in the upper part was thicker than that of lower part from the begining, and above the $8^{\circ}C$ in the beginning upper part was thinner with concave, but with time thicker the upper part, vanishing concave.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.713-720
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• 2000

The directional response of strength and deformation on the rocks acting by external loads is called by strength and deformability anisotropy, respectively. Peak strength and its failure criteria of anisotro rocks have been studied and reported. Many authors have investigated in detail the behavior of triaxial peak strength of anisotropic rocks(Jaeger 1960, McLamore & Gray 1967, Hoek & Brown 1980, Ramamurthy & Rao 1985). They concluded that the triaxial strength of anisotropic rocks varies according to the inclination of discontinuity in specimens. And, the minimun triaxial strength occurs in the specmen with 60° of inclination angle ; and specimens with 0° or 90° inclination have maximum triaxial strength. Based on the experimental result, the behavior triaxial strength is investigated. The triaxial compression tests due to the angle bedding plane have been conducted and the material constants, 'm' and 's', cohesion and angle of friction and nonlinear strength parameters to fit for the failure criterion were derived from the regression analysis. And, the experimental date are employed to examine three existing failure criteria for peak strength, provided by Jaeger, McLamore and Hoek & Brown and Ramamurthy & Rao. For a shale, the suitability of the failure criteiria of triaxial peak strength for anisotropic rocks is discussed.

• 대한기계학회논문집B
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• 제40권8호
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• pp.527-533
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• 2016

대기압 상태인 물의 내부에 설치된 튜브의 경사각이 풀비등 열전달계수에 미치는 영향을 확인하기 위하여 새로운 실험식을 개발하였다. 실험과 기존에 발표된 결과들에 대한 조사를 통하여 431개의 실험값을 결정하였으며, 회귀분석 기법으로 비선형 최소자승법을 사용하였다. 열유속($0{\sim}120kW/m^2$), 경사각($0^{\circ}{\sim}90^{\circ}$), 튜브 길이를 직경으로 나눈 값(18~42.52)을 주요 매개변수로 선정하였다. 새롭게 개발된 상관식은 약간의 예외를 제외하면 실험값을 ${\pm}18%$ 범위 내에서 잘 예측한다.

• 한국가시화정보학회지
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• 제18권1호
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• pp.67-73
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• 2020

Flexible structures have been adopted in heat transfer systems as vortex generators. The flexible vortex generators immersed in a flow show a self-sustained oscillatory motion, which enhances fluid mixing and heat transfer. In the present study, the vortex generators in a two-dimensional channel flow are numerically investigated, and they are symmetrically mounted on the upper and lower walls with an inclination angle. The momentum interaction and heat transfer between the flexible vortex generators and the surrounding fluid are considered by using an immersed boundary method. The inclination angle is one of the important factors in determining the flapping kinematics of the flexible vortex generators. The flapping amplitude increases as the inclination angle increases, thereby enhancing fluid mixing. The heat transfer is enhanced up to 80% comparing to the baseline channel flow.