• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.122-128
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• 2000

Aerodynamic optimization of an automotive air-conditioning blower is a hard task because of the highly complex flow phenomena related to three-dimensional flow separations and the unsteady nature caused by the interaction between primary and secondary air flows throughout the fan. In this paper, an aerodynamic study on a forward-curved centrifugal fan has been carried out Firstly we obtained the fan performance curves versus flow rates showing its unstable nature in the surging operation range. Secondly aerodynamic characterizations were carried out by investigating the velocity and pressure fields in the casing flow passage using a 5-hole pilot probe, at different operating conditions. Surface flow pattern near the cut-off area exhibits similar flow behavior above the best efficiency operating point, although the pressure level increases substantially with the Increase of flow rate. Vorticity in the casing passage flow occurs in all (low rates, downstream from the r-Z plane $\theta$=120 deg., where the position of its core changes with the circumferential location. Although complex, the general flow behavior were common, giving insight in its main aerodynamic features.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.148-156
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• 2014

The objective of this study is to compare NOx emissions from light duty diesel vehicles measured from on-road tests that conducted under various driving routes and seasonal conditions. We measured real-driving NOx emissions using PEMS, portable emissions measurement system, under the urban, rural and motorway road traffic conditions. On-road tests were repeated at summer, fall and winter season. The accumulated driving distance is more than 1,200 km per each vehicle. Route average NOx emission factors were compared among nine route-season combinations. The emission characteristics of each combinations were investigated using time series mass emission rates and vehicle operation-based emission rates and activities, which is based on U.S. EPA's MOVES model. Most concerned route-season combination is "urban road condition at summer", which shows two to eleven times higher NOx emissions than other combinations. The emission rates and activities under low speed operating conditions should be managed in order to reduce urban-summer NOx. From a NOx control strategy perspective, the exhaust gas recirculation, EGR, is observed to be properly operated under wide range of vehicle driving conditions in Euro-5 vehicles, even if the air conditioner turns on. In high power demanding conditions, the effect of overspeeding could be more critical than that of air conditioner activation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.1
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• pp.56-61
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• 2005

Indoor air quality becomes of a concern recently in view of human health. This study investigates the air diffusion performance and the air change efficiency of a classroom, when outdoor air is introduced in addition to the heating/cooling operation of a ceiling-mounted heat pump. A CFD analysis has been performed to investigate the effect of the discharge angle of the air jets from the heat pump for both parallel and series types of outdoor air system. It is observed that the series type creates more uniform indoor environment compared to the parallel type in general. It can be concluded the discharge angle should not be larger than 40o for the parallel type, in order not to generate thermal stratification in the room.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.199-206
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• 1997

The inner pulley is an automobile component used as air conditioner clutch assembly. In cold forging of inner pulley, the design requirements are to keep the same height of the inner rib and outer one, and to make uniform the hardness distribution in the forged product. In industry, the design of forging processes is performed based on experience-oriented technology, that is, designers experience and expensive trial and error. Using the rigid-plastic finite element simulations. we design the optimal process conditions, which has a preforming operation. Also the final product configuration of forging has to be designed again in view of metal flow involved in the operation, derived from the finite element simulations. The forged pulley is investigated by checking the hardness distribution and it is noted that distribution has improved to be even and high enough for industrial application.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.525-527
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• 2009

본 논문에서는 자동차 공조부품인 리시버드라이어로서 플랜지와 바디로 구성되어 있다. 리시버드라이어는 냉매 중 포함된 습기 및 기타 불순물을 차단하는 부품으로서 사이트글라스가 부착되어 냉매의 흐름의 상태를 알 수 있다. 또한 압력 밸브가 부착되어 있어 냉매 회로의 압력과 온도가 상승하면 녹아서 냉매를 배출하므로 배관이나 부품들의 압력에 의해서 파괴되는 것을 방지 할 수 있다. 최근 경제적 성형에 관심이 많아 대표적 성형공정인 냉간단조를 적용하여 소재 회수율 및 절삭 비용 등을 절감하는데 목적을 두었다. 냉간단조를 적용하여 자동차 공조 부품인 플랜지와 바디를 개발하는데 공정설계, 금형설계, 금형제작 기술을 확보하였다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.6
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• pp.269-277
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• 2005

In this paper, designs of an Interior Permanent Magnet Synchronous Motor (IPMSM) and its motor driver for 42V automotive air condition system are introduced. The characteristics of the IPMSM are predicted by using d-q equivalent circuit having the parameters, such as current phase angle, d-q axis inductances, core loss resistance, etc. The experimental and analysis results of the prototype are compared to show validity of the analysis method, and to give analyzed characteristics in detail. As the result, an improved IPMSM is designed to widen the operating speed limit of prototype; a cost effective AC drive are considered at the same time.

• Proceedings of the ESK Conference
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• 1987.04a
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• pp.143-148
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• 1987

The Design of automotive IP must be designed for improving safety, and for satisfying the consumer's preference and for enlarging the usability of various gauges and information displaydevices. Also, these objects become more important by regarded and will be treated very sensitively for the next-generation vehicle concepts. Therefore, Automotive IP must be designed to adjust these trends, besides accord with car-inner lifestyle. One of these concept's designs is to apply Human Sensibility Ergonomics. This study suggestes the driver-centered design of the IP components that focused on the audio unit and HVAC(Heat and Ventilation Air Conditioner) through cognitive experiment. Primarily, analyzed components of IP in use, then, combined these components (especially, the number and arry of buttons, the position of LCD panel, etc.) nd designed some sample images(prototypes) the same as real size. After the subjects looked at the sam ples at the interval of 0.2/0.4/0.6 seconds, subjects should fill out the given forms from their memory. Then, the optimal prototype of IP was designed in respect to the correctness of cognition. The results will show the basic guideline of optimal design of IP that in the case of aaudio unit, the position of LCD, the array and the number of channel, in the case of HVAC, the position of LCD, TEMP button type and other button types.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.11
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• pp.1635-1646
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• 1998

The present study investigated the effects of geometric parameters considered on the performance of an automotive scroll compressor by assuming ideal, semi-real and real gases for R-134a. The geometric parameters were center thickness of scroll, height of scroll and the size of discharge port. Fourth-order Runge-Kutta method was applied to solve the thermodynamic equations, leaking rate equation and the equation of motion of discharge valve for ideal, semi-real, and real gases. The volumetric and adiabatic efficiencies for semi-real and real gases differed little, but those for ideal gas differed by 18% and 25% compared with those for real gas at 2,000rpm. The volumetric efficiency changed little as the design angle of scroll (${\gamma}$) changed, but the adiabatic efficiency at ${\gamma}$ of $34^{\circ}$ was higher by 2.4% than that of $147^{\circ}$ for 2,000rpm. The volumetric and adiabatic efficiencies at scroll height of 29.8mm were higher by 1.7% and 2.8% than those of 65.8mm. The volumetric efficiency changed little as the size of discharge port changed, but the adiabatic efficiency increased a little as the size of discharge port decreased.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.1
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• pp.45-50
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• 2012

The plate fin and tube type of heat exchanger is widely used in air conditioner, and the heat exchanger is assembled by the mechanical expansion of copper tubes and fastening the aluminum fin. The objective of the present study is to investigate how the mechanical expansion of copper tube affects on the heat transfer performance of a plate fin and tube type heat exchanger. This study has been performed by experimental and numerical methods. The numerical and experimental results show that the tube expansion ratio has a influence on the heat transfer performance. Within the tested expansion ratio, the contact pressure shows the peak value and it decreases as the expansion ratio increases. Air-side heat transfer coefficient increases until the expansion ratio reaches 1.23, and then decreases with the similar pattern to the contact pressure. Also, contact heat transfer coefficient shows the maximum when the contact pressure is highest as well as the air-side heat transfer coefficient.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.2
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• pp.162-168
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• 2007

This paper presents the effects of thermoelectric module arrangement on the cooling performance of an air conditioner using thermoelectric module. A prototype of air cooling system, employing several thermoelectric modules, has been designed and built. The evaporative cooling technique is adopted for hot side of the module. The number of thermoelectric module in the system has been varied in the range of $2{\sim}8$. The optimal operation conditions, such as input power to the thermoelectric module, fans and pump, have been determined for each arrangement of the system and the cooling performance has been compared under the optimal operation. It is found that both cooling capacity and COP are increased as the number of thermoelectric module increased. It is also found that cooling capacity can be improved by connecting the thermoelectric modules in series than in parallel, while the COP is little affected.