• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.3
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• pp.35-41
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• 2001

In recent applications, map controlled thermostat has been adapted to optimize engine cooling system and vehicle cooling system. First of all, this strategy is focused on improving fuel consumption rate and reducing emissions, especially unburned hydrocarbon. The object can be obtained through controlling engine metal temperature by varying engine coolant temperature with engine load and speed. To achieve this goal, it is necessary to understand the characteristics of engine metal temperature and heat rejection rate to coolant. From the results of tested engines, it is obvious that fuel consumption rate has more dominant effect on engine metal temperatures than the corresponding engine power does. Also, Re-Nu relation which shows heat rejection rate to coolant in function of air-fuel mixture and engine specifications has been studied. Also, the empirical Re-Nu relation at full loaded engine was developed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.143-149
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• 2009

Recently, according to the tendency to the more comfortable automobile, the improvement of performance of the cooling fan is required. The performance of cooling fan is affected by many peripheral parts, such as radiator, condenser, engine block and etc. Therefore, it is important to consider the effect of peripheral components on the fan performance in design and analysis stages. In this paper, the performance of automobile cooling fan is investigated experimentally by using the large capacity fan tester based on the ASHRAE and the AMCA standards. In particular, the various spacing between cooling fan and engine block are considered to obtain the effect of engine block. An empirical relation between the fan flow rate and the spacing was proposed.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.58-67
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• 2003

An automotive engine cooling system is closely related with overall engine performances, such as reduction of fuel consumption, decrease of air pollution, and increase of engine life. Because of complex reaction between each component, the direct experiment, using a vehicle, takes high cost, long time, and slow response to the system change. Therefore, a computer simulation would provide the designer with an inexpensive and effective tool for design, development, and optimization of the engine cooling system over a wide range of operating conditions. In this work, it has been predicted the thermal performance of the engine cooling system in cases of stationary mode, constant speed mode, and city-drive mode by mathematical modelling of each component and numerical analysis. The components are engine, radiator, heater, thermostat, water pump, and cooling fans. Since the engine model is the most important, that is divided into eight sub-sections. The volume mean temperature of eight sub-sections are simultaneously calculated at a time. For detail calculation, the radiator and heater are also divided into many sub-sections like control volumes in finite difference method. Each sub-section is assumed to consist of three parts, coolant, tube with fin, and air. Hence it has been developed the simulation program that can be used in case of design and system configuration changes. The overall performance results obtained by the program were desirable and the time-traced tendencies of the results agreed fairly well with those of actual situations.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3294-3299
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• 2007

These days the exhaustion of petroleum resources and environmental problems are getting serious. Many researchers are focused on low emission and high performance vehicles. Therefore, we should concern about emission regulation when we design a new car. In this study, we investigated the characteristics of the traditional mechanical engine cooling systems which control the engine temperature using engine speed and wax type thermostat. This experiment used three components which are Radiator fan, water pump and water valve controlled by an electronic system based on the engine status (load, speed). We elucidated how different between traditional mechanical cooling system and electronic cooling system which control coolant temperature and coolant flow rate in a DI diesel engine in this paper. The results revealed a fuel saving and an emission (CO, HC) reduction on NEDC cycle.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.58-63
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• 2016

This paper presents a study of heat dissipation away from the fuel combustion of a marine diesel engine. These engines are operated for long periods under high load conditions: so cooling systems are necessary for radiation and control of the high temperature levels. In the study, each component of the water cooling system was developed to achieve improvements in cooling and safety. Heat transfer considerations and arrangement design for the components were important and an intercooler and exhaust manifold incorporated. An optimization of the cooling water's flow path was achieved subject to the need for convenient maintenance. The 750Ps marine diesel engine was used for performance testing of the cooling system. The test results showed adequate cooling performance improvement.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.341-346
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• 2000

A numerical simulation has been carried out for the engine cooling system. It is the important element to analysis of heat transfer process in cooling system for an automotive engine. Thus, the purpose of this simulator is to present useful information at the early stages of the design of the cooling system by enabling the development engineer to predict performance trends. This program has useful window interface for analysis of the cooling system and it is convenient for user to control data with relational database. The system was simulated and compared with experimental data. As a result, the inlet, outlet temperature of the radiator by the simulator agrees well with it. It is concluded that this simulation program is available in developing the cooling system for a new car.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.1
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• pp.119-130
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• 2008

Diesel engine is one of the most expensive and important components in a ship. Many researchers are interested in increasing the performance of diesel engines. Design of an optimum cooling system should also contribute to the enhancement of the performance as well as the efficiency of engines. In this study, we investigated the flow pattern within the cooling system of a marine diesel engine by using numerical simulation prior to the study of the heat-transfer problem. The engine cooling system is composed of five cooling units each unit containing a water-jacket and a cylinder head. Based on the calculated data, we also conducted theoretical analysis that can predict the flow-rate delivery in each of the five units.

• Journal of Biosystems Engineering
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• v.18 no.1
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• pp.3-14
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• 1993

This study was conducted to obtain basic data which affected engine performance of the power tiller being widely used in the rural area. Among the various factors being influenced engine performance, factors of radiator, of capacity of cooling water, and of efficiency of cooling fan were considered as the major factors in this study. Because diesel engine being used to power tiller are scarce of cooling water, it is over-heated in time of rated power. Therefore, a experiment was performed to determine the capacity of cooling water of engine with circuit system of cooling water adhered.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.10-17
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• 2001

The performance of a radiator is generally determined using a wind tunnel, in which the air velocity is uniform. However, when it is installed in a car, the distribution of the air velocity becomes nonuniform due to front-end openings, cross members, and horns etc., resulting in lower performance. In this study, several underhood flow simulations have been first performed to get flow rates and velocity distributions over the radiator. Secondly heat release rates are calculated by both a performance curve and a radiator model. Finally, using an engine cooling system simulator, radiator-top-tank temperature is predicted and the variations of heat release rate and radiator-top-tank temperature with nonuniformity of air velocity distributions are analyzed. The results show that the current engine cooling model successfully accounts for the nonuniformity effects that should be considered for higher accuracy in predicting engine cooling performance.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.6
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• pp.134-139
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• 2004

It is known that over 60% of engine power is dissipated into circumstance, cooling water and cooling oil without any conversion into useful work. Following the first law of thermodynamics, it is possible that heat loss to cooling water can be converted into mechanical work through crankshaft. But in case that the engine is operating without any cooling effect, the serious problem unsolved so far is the engine durability. In this study, LHR(Low Heat Rejection) engine was introduced as one of the promising engine and several useful qualitative and quantitative data were drawn.