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.

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.

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.

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.

배기계에서 비정상 가스의 소음특성에 관한 해석

박근욱,신문섭,장옥수,오율권 朝鮮大學校 機械技術硏究所 1998 機械技術硏究 Vol.1 No.1

일반적으로 자동차의 소음은 주로 엔진에서 발생되어서 공기를 통해 전달되는 소음과 흡·배기계를 구성하는 tube 또는 Chamber를 통하여 전달되는 소음으로 구성된다. (1) 차량소음의 주요 소음원은 흡기계의 흡기소음과 배기계의 배기소음을 들 수 있으며, 소음중 배기소음은 도시소음의 주된 요인이며 차량의 승차감을 저해하는 간접적인 원인 중의 하나이다. 따라서 일반적인 자동차에는 반드시 소음기 즉, 머플러를 부착하여 소음을 어느 정도 이하로 감소시키게 되어 있다.(2.3) 전통적으로 소음기에 대한 연구는 주로 음향필터이론에 바탕을 두고 진행되어왔으나 음향필터이론은 배기소음기의 소음감쇄작용에 대한 체계적인 이론적 설명을 제시하지는 못했다. 음향에너지의 소산(Dissipation)을 고려하지 않고 음향이론상에서 배압을 예측하는 것은 불가능하다.(4) 그로므로 본 연구에서는 내연기관의 다양한 배기시스템에 대하여, 비선형 작용을 고려하므로서 1차원 비정상 등엔트로피 분석을 이용한 특성법(5)을 사용하였으며, 이러한 분석법에 배기시스템내에서 유동현상의 완전한 처리를 위하여 준정적 유동 접근법에 근거한 경계모델을 포함시켰다. 또한 이론의 타당성을 검증하기 위하여 최근까지 연구되어져온 블로오등을 사용한 시험결과는 달리 로터리 밸브 시뮬레이터를 사용하여 압력-시간 파형을 측정하였으며 측정된 결과와 계산된 결과를 비교하여 맥동 압력파 전파 특성을 확인하였다. 본 연구의 목적은 엔진 성능과 관계된 비정상 가스유동의 거동특성을 유한진폭과 이론을 사용하여 성공적으로 예측하는 방법을 제시하는데 있으며, 각 머플러에 대한 소음감쇠특성 및 소음기의 일반적인 특성을 분석하는데 있다. This thesis describes a theoretical and experimental investigation of the pressure propagation characteristics of some basic internal combustion engine exhaust systems. The mufflers of internal combustion engine have been applied to control the exhaust noise for many years. The greatest reduction in engine noise is generally achieved through proper muffler selection. Although proper muffler selection may seem relatively simple, a numbers of considerations must be made. Additional considerations in the reduction of exhaust system noise include proper selection of piping lengths and diameters, proper mounting of exhaust system components, and proper positioning of the exhaust outlet. In the present work, account is taken of the nonlinear behavior. For sections of parallel pipe, an one-dimensional unsteady homentropic analysis is employed, and a numerical solution is obtained with the aid of a digital computer, using the concept of characteristics. This analysis is than combined with boundary models, based on a quasi-steady flow approach, to give a complete treatment of the flow behavior in the exhaust system

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.

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.

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.