• 한국자동차공학회논문집
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• 제12권3호
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• pp.27-36
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• 2004

A Numerical analysis has been used to predict the performance in the automotive water pump with double discharge single suction. The influence of parameters such as coolant flow rate, rotational speed, ratio of blade height and clearance has been investigated. Also, the prediction of hydraulic performances such as static pressure rise, shaft power, hydraulic power and pump efficiency is carried out on the water pump including an impeller and a volute casing. A full size water pump test bench has been developed to validate the CFD flow model. Discharge flow rate, suction pressure, discharge pressure, rotational speed and torque measurements are provided. Coolant temperature is 8$0^{\circ}C$, water tank pressure is 1 kgf/$\textrm{cm}^2$ and flow rates vary.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.237-242
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• 2009

A steam Rankine cycle was considered to recover waste heat from the exhaust gas of an automobile. Conceptual design of a swash plate type expander was practiced to convert steam heat to shaft power. With the steam pressure and temperature of 35 bar and $300^{\circ}C$ at the expander inlet, respectively, the expander was estimated to produce the shaft power output of about 1.93 kW from the exhaust gas waste heat of 20 kW. The expander output increased linearly accordingly to the amount of exhaust gas waste heat in the range of from 10-40 kW, and the Rankine cycle efficiency was more or less constant at about 9.6% regardless of the waste heat amount.

• 대한안전경영과학회지
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• 제18권4호
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• pp.179-183
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• 2016

The purposes of this research are to modelize test system of SM TESTING by ARENA, software, input several items of specimen's testing process, resources of system and transfer loop, etc, give a hypothesis and then, obtain results reducing the efficiency of the whole system finally by overload of specific facilities in the testing system through the simulation so as to obtain several materials such as specimen and testing facility, transfer loop, etc. by simple and various forms without any necessity of numerical modelization. It will add facilities of over load and reduce facilities with low operation rate, so increase the efficiency of the system.

• International Journal of Precision Engineering and Manufacturing
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• 제3권3호
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• pp.28-36
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• 2002

The continuously variable transmission (CVT) mechanism considered here is the output coupled type which combines the functions of a 2K-H I type differential gear unit and a V-belt type continuously variable unit (CVU). One shaft of the CVU is connected directly to the output shaft and another shaft of it is linked to the differential gear unit. It is shown that some fundamental relations (speed ratios, power flows and efficiencies) for twelve mechanisms previously described are valid by various experimental studies, six of them produce a power circulation and the others produce a power split. Parametric analysis is carried out in relation to the efficiency, speed ratio and power ratios in order to assist in the design of an optimum configuration. Some useful properties associated with power flow modes also are discussed in the output coupled type continuously variable transmission.

• 자원리싸이클링
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• 제9권6호
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• pp.23-30
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• 2000

현재 용도 폐기된 플라스틱의 대부분은 소각 또는 매립 처리되고 있기 때문에 사회적 문제가 되고 있다. 폐플라스틱을 효과적으로 재활용하기 위한 방법론의 하나로서, 고로공정에서의 연료화 기술이 개발되어 유럽 및 일본의 선진 제철소에서는 실용화 단계에 이르고 있다. 본 연구에서는 포항제철 주물선고로 풍구 4본을 대상으로 2종류의 폐플라스틱 130 ton을 연속적으로 시험취입조업을 하였다. 취입비 13.8kg/thm까지의 코크스 치환율은 0.98kg-coke/kg-plastic으로 평가되었으며, 폐플라스틱의 종류에 따른 영향은 나타나지 않았다. 폐플라스틱의 취입량이 증가할 수록 송풍압은 증가하였으며, 고로내 통기성도 악화되어 노체 하부의 열부하가 증대하는 경향을 나타냈다. 또한 폐플라스틱 취입량이 증대될수록 노정가스 이용율과 shaft효율이 감소하는 것으로 해석할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.312-316
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• 2002

Recently, mixers are being widely used in the water purification plant in order to increase the filtration efficiency. It has been found that a severe vibration was being felt on a upper structure of a mixer facility during steady state operation. The cause of the excessive vibration of the structure to which the mixer's shaft is supported has been evaluated through modal analysis on the shaft and vibration measurements during operation. The fundamental natural frequency of the mixer's shaft is found to be around 1.8 Hz and the main vibratory frequency around 30 Hz. It has been tuned out that the main vibratory frequency, 30 Hz is coincident with the fundamental holding frequency of the upper structure, and that the acceleration signal of the upper structure and the displacement signal of the mixer's shaft showed highly coherent to each other. Accordingly, it reveals that the main cause of the excessive vibration is due not to the mixer's vibration but to the natural frequency of the upper structure excited by flow turbulence.

• 동력기계공학회지
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• 제17권2호
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• pp.87-94
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• 2013

Applicability of organic Rankine cycle for a passenger car with 3.5 L gasoline engine to convert low grade waste heat to useful shaft power has been numerically studied. Working fluid is R134a, and the Rankine cycle is composed of boiler for recovering engine cooling water heat, super heater for recovering exhaust gas heat, scroll expander for converting waste heat to shaft power, condenser for heat emission, internal heat exchanger, and feed pump. Assuming efficiencies of 90% for the heat exchangers, 75% for the scroll expander, and 80% for the feed pump, the Rankine cycle efficiency of 5.53% was calculated at the vehicle speed of 120 km/hr. Net expander shaft output after subtracting the power required to run the pump was 3.22 kW, which was equivalent to 12.1% improvement in fuel consumption. About the same level of improvement in the fuel consumption was obtained over the vehicle speed range of 60 km/hr~120 km/hr.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.421-426
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• 2003

Recently, mixers are being widely used in the water purification plant in order to increase the filtration efficiency. The mixer normally consists of impeller, shaft, hub, reduction gear, and the driving motor. It is one of the key design issues to confirm that the vibration caused by the rotation of the shaft should not coincide with the natural vibration frequency of the shaft itself. The vibration characteristics of the hydrofoil type mixer, which is the most widely used in real plants are evaluated through the finite element modeling and verified by experiment using the mock-up facility. The fundamental natural frequency of the mixer's shaft is found to be around 1.8 Hz which showed in good agreement with the experiment. The higher natural frequencies to the 2nd, 3rd, and 4th modes are also verified by the experiment. Thus the developed model is to be utilized for the structural design of the real mixer system.

• Ocean Systems Engineering
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• 제11권4호
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• pp.373-392
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• 2021

The present paper purposes a numerical evaluation of the Thai Long-Tail Boat propeller (TLTBP) performance by without and with propeller boss cap fins (PBCF) in full-scale operating straight shaft condition in the first. Next, those are applied to inclined shaft conditions. The actual TLTBP has defined an inclined shaft propeller including the high rotational speed, therefore vortex from the propeller boss and boss cap (hub vortex) have been generated very much. The PBCF designs are considered to weaken of vortex behind the propeller boss which makes the saving energy for the propulsion systems. The blade sections of PBCF developed from the original TLTBP blade shape. The integrative for the TLTBP and the PBCF is analyzed to increase the performance using computational fluid dynamics (CFD). The computational results of propeller performance are thoroughly compared between without and with PBCF. Moreover, the effects of each PBCF component are computed to influence the TLTBP performance. The fluid flows around the propeller blades, propeller boss, boss cap, and vortex have been investigated in terms of pressure distribution and wake-fields to verify the increasing efficiency of propulsion systems.

• Journal of Advanced Marine Engineering and Technology
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• 제29권7호
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• pp.713-721
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• 2005

A marine diesel engine should realize optimal operation efficiency while reducing NOx, PM (Particulate Matters) and other emissions. Fuel injection systems that use electronic control can become an effective means of achieving that objective. However. it still needs some accurate and instant information in order to bring its ability into full potential while sailing on the sea. The important information of them are a shaft torque and continuous combustion pressures of all cylinders. The shaft torque and the propeller thrust described in this paper are measured at an intermediate shaft by using a unique principle that one of two electromagnet coils oscillates a vibrating strip which the length changes with force and the other coil picks up the change of the frequency of the vibrating strip. For further reference, the shaft power meter multiplied the torque by the shaft revolution has already had about 750 sets of sales performance. The research presented in this paper started about ten years ago and is concerned with the development of a combustion pressure sensor that uses the same principle. Recently, the pressure sensor which bears continuous operation has been developed after a hard struggle, that is, the system that consists of a shaft horsepower meter, a propeller thrust meter and a combustion pressure sensor has been completed and has been shown to be reliable. This paper describes the configuration of this system, the material of the combustion pressure sensor, the principle of that, and the improving point of the sensor, and, we finally consider the use of this system.