CFR機關에서 M-I-A 混合物의 燃燒速度

吳栗權,鄭洛奎 조선대학교 동력자원연구소 1988 動力資源硏究所誌 Vol.10 No.1

The study of the burning velocities in methanol-Indolene-Air mixtures has been completed in a CFR engine. The investigation included measurements of ignition delay, combustion interval, and flame speed over a wide range of compression rations(5.0 to Knock Limited Compression Ratio) and methanol concentration (0 to 100%). The result indicated that by adding methanol to indolene, ignition delay, combustion interval and MBT (Minimum Advanced for Best Torque) spark advance decreased. Adding methanol to indolene results in an increase in flame speed, burning velocity and the Knock Limited Compression Ratio.

작동유체의 등온 가열 상태에서 펌프의 이상유동 특성에 관한 실험적 연구

오율권,유영태,이용헌,서동표 조선대학교 생산기술연구소 1996 生産技術硏究 Vol.18 No.1

This study is to examine the effects of entrained air on the pump performance in a centrifugal pump. Using a 1/10 scale model pump. which is designed and manufactured to simulate two phase flow performance of the reactor coolant pumps of Y.G.N #3 and 4. a set of experiments was executed with water and air mixtures at heated state of 50℃ and at atmospheric pressure. A head loss coefficient. which is defined as a nondimensional ratio of the difference of theoretical and actual pump head coefficient in a single phase. ◁화학식 삽입▷ (원문을 참조하세요) was determined as a function of void fracrtion, α , and flow coefficient, Φ. The calibrated mass flow rates of air and water were used to calculate void fraction using the void meter of the conductivity probe type. compensate the defect of drift flux model and calculate the void fraction. In particular. the flows were stoped when the void fraction was about 0.13.

배관내 자유수면에서 와류현상에 대한 연구

오율권,장완호,이종원,김상녕 대한기계학회 1992 대한기계학회논문집 Vol.16 No.11

In order to prevent the decay heat removal system from failure due to air entrainment or free surface vortex in the piping system, a set of simulating experiments for the midloop operation of nuclear power plant was performed. Through these experiments, a relation between the dimensionless numbers, such as submergence H/d, froude number, reynolds number, was found. However, the effect of reynolds number was negligible for the operation conditions of Nuclear power plant. It was also found that the perturbation of the system by the disturbance such as pump start, valve operation, etc., has a strong effect on the free surface vortex. Furthermore, from a view point of reactor safery, a modified inlet device of reducer type is strongly recommendable for the prevention of air entrainment. 본 연구에서는 국내 원자력 발전소중 영광 3,4호기의 설계자료를 토대로 1/6 크기로 축소한 모델실험을 통해서 공기흡입이 발생하는 임계수위를 결정하는 상관식을 개발하였으며 또한 공기흡입구를 reducer type으로 개선함으로써 공기흡입을 방지할 수 있음을 밝혔다.

異質材의 切削抵抗에 關한 硏究

吳栗權,沈在基 조선대학교 동력자원연구소 1983 動力資源硏究所誌 Vol.5 No.1

This paper dealt with the experiment of the Back Rake Angle on the cutting resistance of different material. The obtained result are as follows ; (1) When the back rake angle is increased, the magnitude of the three component of cutting force-the one of vertical component, of radial component and of axial component are gradually decreased. And in view of %for each component of the cutting force, the% of v.c is increased, the%of r.c is decrased and the% a.c is changed a little. (2) When the feed is increased, the magnitude of three component, the% of vertical and a.c are increased but the% of r.c is increased. (3) Three component of cutting force by the amount of feed, in the case of test material B, increased averagely 28.8% on the v.c, 84.1% on the r.c and 96.1% on the a.c when feed revealed 0.2mm/rev rather than 0.1mm/rev. (4) The proportion of three component of cutting force in the case of 0.1mm/rev feed on the v.c, r.c and a.c respectively reveals 55.8% 35.6% 8.6% in the base metal zone 56% 35.3% 8.6% in the heat affected zone and 55.8%, 35.7^, 8.4% in the weld zone according to the test material B. (5) The cutting force of different material are decreased in squence of bond zone, weld zone, base metal smaller than that of base metal zone then 1 think, this phenomenon is occurre because the heat affected zone has the properties of free-cutting steel.

旋回火炎의 構造에 關한 實驗的 硏究

吳栗權,河鈺男,洪明錫 조선대학교 동력자원연구소 1984 動力資源硏究所誌 Vol.6 No.2

This study presents the flame structure of swirling flow when there changes the equivalence ration and swirling number of fuel-air mixture. The conclusion of this study are as follows; 1) The configuration of vane angle in swirler flame including swirler number and equivalence ration is a important variation to decide the structure of flame. 2) In case of vane angle 45˚(s=0.673) of swirler the temperature distribution of flame was the highest compared with the other angle of swirler. 3) Generally the temperature of center field h=20 ~40㎜ was low but the circumference temperature was high and vivid combustion reaction was occurred in the around of the flame.

Ladle 내에서 기포에 따른 액상 영역의 유동학적 특성에 관한 가시적 연구

오율권,서동표,양호동 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

In the present study, the gas injection system based on air-water model was designed to investigate the fluid-dynamics characteristics of liquid zone into a ladle. PIV system and camera techniques were applied to analysis flow patterns at the liquid zone. Gas flow rate is one of most important factors which could feature a flow pattern in a gas injection system. At low gas flow rate, upward bubble flow induced by buoyancy force is predominant and does not make an impact on mixing due to a weak circulation flow. However, with increasing gas flow rate, the kinetic energy of bubble increases and a strong circulation flow develops in the liquid. Such a flow in the liquid develops vortex and improve the mixing process. Due to the centrifugal force, circulation flow was well developed near both wall sides and upper region respectively.

Air-Water 모델에서 기포특성에 관한 실험적 연구

오율권,서동표 한국산업안전학회 2003 한국안전학회지 Vol.18 No.1

The structural development of air-water bubble plumes has been measured under different condition on air flow rate in a cylindrical bath. The time-averaged structure of plumes has been measured with an oscilloscope and an electro-conductivity probe. The temperature of bubbles was also obtained by a thermal-infrared camera. Gas volume fraction and bubble frequency were high since bubbles concentrated on the nozzle. In general, their axial and radial values tended to decrease with increasing distance. Bubble temperature reached water temperature within a short time. The present study showed that thermal equilibrium between bubbles and water was completed before bubbles flow became stable.

수치해석을 이용한 음향장내의 압력장 해석에 관한 연구

오율권,양호동,서동표 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

Applying ultrasonic waves in a medium enhance the heat transfer, judging from the facts that applying ultrasonic waves to the liquid medium gives rise to areas of high and low local pressure. Therefore, in the present study, a coupled finite element-boundary element method(FE-BEM) was used to calculate the acoustic pressure in a medium. For the numerical analysis, we performed the process of finite element modeling. This modeling data was converted to the boundary element data by SVS(Structure Vibtation Simulator). SVS programmed was composed of FORTRAN language and based on a coupled FE-BEM. The results of numerical analysis reveal that acoustic pressure is increased by 60% at the ultrasonic intensity of 340W and the higher acoustic pressure distribution near two ultrasonic transducers.

기체 주입 Ladle내에서 유동특성에 관한 연구

오율권,서동표 조선대학교 에너지.자원신기술연구소 2003 에너지·자원신기술연구소 논문지 Vol.25 No.1

In the air-water model, the characteristics of flow parameters were experimentally investigated. When gas was injected into the liquid bath, several flow patterns were observed bubble-liquid plumb, the spout flow that occurred at the free surface, liquid circulation flow by bubble's behavior, etc. In the pure liquid region, the large and small several vortices were formed and irregularly circulated. These irregular repetition and circulation play a important role of mixing in the bath. The vortices were developed in the upper and the side wall regions and the movement of flow in the low region was very small. It is known as "dead zone". The bubble rise velocity in the bottom region was relatively lower than in the upper region because the energy generated by bubbles' behavior in the near nozzle region was almost converted into kinetic energy. But bubble rise velocity increases with the increasing the axial distance since kinetic energy of bubbles is added to buoyancy force.

고도로 과열된 액체분사의 분해의 메카니즘에 관한 연구

오율권,정낙규 조선대학교 동력자원연구소 1988 動力資源硏究所誌 Vol.10 No.2

Delay time and jet divergence angle measured were studied for slashing jets at high degrees of superheat. n-pentane, n-hexane, and ethanol were injected into nitrogen at two injection pressures and for three nozzle diameters. Proposed hypothesis for the delay time based on homogeneous nucleation are not confirmed by our experimental data. The assumption that the spray angle is related to the heat-transfer-controlled bubble growth appears to be supported by our data but important details concerning the number of bubbles in the jet and the state of the vapor in the bubble at breakup have not yet been properly explained. Both delay time and jet divergence angle are found to be sensitive to the degree of superheat and liquid properties, influenced by the liquid pressure and insensitive to jet diameter.