• Journal of the Korean Institute of Gas
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• v.25 no.5
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• pp.11-18
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• 2021

Since hydrogen has the lower minimum ignition energy than that of gasoline, hydrogen could be also appropriate for the IC engine systems. However, due to the low ignition energy, there might be a 'back-fire' and 'pre-ignition' problems with hydrogen SI(Spark-ignition) combustion. In this research, cooling effects of intake gas mixture on the improvement of the maximum power output were evaluated in a 2.4 L SI engine. There were two ways to cool intake gas mixtures. The first one was cooling intake fresh air by adjusting inter-cooler system after turbocharger. The other one was cooling hydrogen fuel before supplying by using heat ex-changer. Cooling hydrogen was performed under natural aspired condition. The result showed that cooling fresh air from 40 ℃ to 20~30 ℃ improved the maximum brake power up to 6.5~8.6 % and cooling hydrogen fuel as -6 ℃ enhanced the maximum brake power likewise.

• Transactions of the KSME C: Technology and Education
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• v.2 no.1
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• pp.57-63
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• 2014

In this paper new air-cooling system utilizing Stirling engine was proposed for improving efficiency in solar photovoltaic power generation. The solar cell plate was equipped with semi-circular channel for air flow on the backside. Beta-type Stirling engine was installed on the plate and its flywheel was connected to a motor fan by a transmission belt. A forced convective air flow for heat radiation was generated by the operation of the self-starting Stirling engine. The performance tests for power generation of solar cell with or without the proposed air-cooling system were conducted under halogen lamp. From the experimental results, it was found that decline in output voltage of the solar cell with proposed cooling system was 25% less than that of the solar cell without cooling system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.33-34
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• 2005

The internal state of an automotive engine is very severe. A piston exposes burnt gas of over $2000^{\circ}$ nd is shocked by high pressure at the time of explosion. Furthermore strong friction is caused by high speed motion. A study on the cooling of the piston requires because the cooling and lubrication of the piston has an effect on the life and efficiency of engine directly. The previous system of oil jet cooled only the bottom of the piston. In order to improve the cooling efficiency, the oil gallery is made inside the piston, and oil flows into the oil gallery. The flow rate of oil at the entrance of oil gallery is important because of the cooling efficiency. The purpose of this study is the investigation of fluid flow characteristics of oil jet and flow rate into the oil gallery.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.97-100
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• 2006

An ejector is designed for the purpose of engine bay cooling and exhaust gas cooling. The primary flow of the ejector is the exhaust gas of the turboshaft engine. The mass flow of secondary flow is calculated by using the approximate analytic equation. For the purpose of verification of approximate method, comparison is made with the results of Navier-Stokes turbulent flow solution. According to the results of CFD, the mixing of two flows is incomplete due to the short length of mixing duct.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.196-201
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• 2003

Axial fans are widely used for automotive engine cooling device due to their ability to produce high flow rate to keep engine cool. At the same time, the noise generated by these fans causes one of the most serious problems. Especially, engine cooling fan noise in idle condition of a car is noticeable. Therefore, the high efficient and low-noise fan is seriously needed. When a new fan system is designed, system resistance and non-uniform inflow are the key factors to get the high performance and low noise fan system. In this study, experimental study on the fan and system was carried out and brought a successful result of performance and noise from a designed fan. And through the modification of the fan system, the fan produced more flow rate and became less noisy.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.117-127
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• 1997

To maintain the reasonable temperature in the engine is very important to keep the steady combustion state of engine and to prevent increasing of lubricant consump- tion, deteriorating of lubricant, shortening of the life time of engine and decreasing of material strength. The method of energy balance for devided elements of radiator is considered to analyse the performance of radiator. Th data of engine test and vehicle cooling tunnel test are applied to program for calculation of radiator outlet temperature, and this result is compared with outlet temperature of vehicle cooling tunnel test. As a result, the radiator outlet temperature by numerical analysis agrees well with that by experiment. It is concluded that this simulation program is available in developing the cooling system for a new car.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.106-111
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• 2006

Combustion test facility for liquid rocket engine using kerosene and liquid oxygen has been developed for the purpose of cooling and performance study. Test engine of thrust under 1.0 KN can be evaluated, and the real combustion test ensures a good operation of the combustion test facility. Combustion test facility will be modified to supply natural gas and liquefied natural gas as fuel and to give a regenerative cooling test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1774-1781
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• 2012

There are some efforts to improve the performance of electrical heat pump(EHP) and replace it with an alternative cooling equipment such as gas engine-driven heat pump(GHP), a gas cooling equipment, in order to solve the problem of summer electricity supply through reducing the summer electricity peak. This paper analyzes cost-benefit in accordance with replacement of electrical cooling system by gas cooling system using california standard test and sensitivity analysis of some scenarios.

• Korean Journal of Agricultural Science
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• v.17 no.1
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• pp.45-51
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• 1990

This study was conducted to obtain basic data for the design of cooling system by the test of engine performance of the power tiller being used widely in the rural area. Among the various factors affecting engine performance, the flow rate of cooling water was considered as the major factor in this study. Motoring loss, output, fuel consumption ratio, torque, heat absorption of cooling water, and thermal efficiency were measured and analyzed based on three flow rates of cooling water such as 15, 20, and $25{\ell}/min$. The results obtained were as follows : 1. Motoring loss of the engine was 1.371 kW at 2,200 rpm., and mechanical efficiency was 79.1% at rated output level. 2. Output power of the engine increased with the flow rate of cooling water increased. 3. BSFC was 282.9g/kW-h at the flow rate of $20{\ell}/min$, and the temperature of cooling water at outlet was $80.9^{\circ}C$. 4. There was a little variation of torque of the engine depending on the flow rate of cooling water. 5. Absorption of heat by cooling water was increased with the increase of flow rate. 6. The highest thermal efficiency of 32.3% at the flow rate of $20{\ell}/min$ was observed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.78-82
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• 2003

The cooling mechanism for a regenerative cooling liquid rocket engine of 10tf-thrust using kerosene as a fuel was studied from the viewpoint of curtain cooling. Based on the concept of a highly-stratified gas flow in the combustion chamber, the cross section of the combustion chamber was spilt into 2 independent parts, core and exterior part. Additional fuel is injected into the exterior section and gas temperature can be reduced in the exterior section. Consequently, the heat flux into the coolant and wall temperature are reduced and the thermal stability of a liquid rocket engine could be improved.