다구찌 기법을 이용한 FCM 가스켓의 강건 설계에 관한 연구

정진은(Jin Eun Chung),안중규(Juengkyu Ahn),양정모(Jeongmo Yang) 한국자동차공학회 2013 한국자동차공학회 지부 학술대회 논문집 Vol.2013 No.5-2

This paper deals with the robust design of the non-asbestos FCM gasket. In order to this, the measurement of the shear based on the design of experiment using the orthogonal table was carried out and the control factors for shear stress using the larger-the-better SN ratios with the Taguchi method were evaluated. In addition, the analysis of variance for SN ratios was conducted. The temperature, pressure, duration time and humidity were selected as the control factors. The orthogonal table L?(3⁴) was made of 3 levels for each factor and the measurement of shear stress was accomplished on the base of the table. Delta statistics of time is the highest value 0.93 and therefore the time affect the largest effect on the shear stress of gasket. Also from the analysis, the shear stress shows maximum at the duration time 80 sec, temperature 200℃, pressure 90kgf/cm2, humidity 60%RH. P values of duration time and temperature as a results of the analysis of variance are 0.037 and 0.098. Therefore the analysis has significant each with 95% and 90% confidence level.

승용차용 터보과급기의 저속 영역 마찰 손실 측정

정진은(Jin Eun Chung),이상운(Sangwoon Lee),전세훈(Sehun Jeon) 한국자동차공학회 2016 한국자동차공학회 학술대회 및 전시회 Vol.2016 No.11

승용차용 터보과급기의 저속 영역 마찰 손실 측정 장치 개발

정진은(Jin Eun Chung),이상운(Sang Woon Lee),전세훈(Se Hun Jeon) 한국산학기술학회 2017 한국산학기술학회논문지 Vol.18 No.1

본 연구에서는 터보과급기의 성능을 저해하는 주요 인자 중 하나인 마찰손실에 대한 연구를 수행하였다. 실제 엔진에서 빈번하게 사용되는 저속 구간에서의 승용차용 터보과급기의 마찰손실 측정 장치를 개발하고, 30,000~ 90,000rpm의 저속영역에서 작동하는 터보과급기의 마찰손실을 측정하였다. 플로팅 베어링 타입의 승용차용 터보과급기를 실험 대상으로 선정하였으며, 마찰손실 측정 장치는 구동 모터, 오일 공급 시스템, 커플링으로 구성되었다. 실제 차량의 저속 운전 상황을 모사할수 있도록 설계, 제작되었고, 회전속도, 오일 온도 및 압력을 실험 변수로 선정하였다. 또한, 마찰손실 측정 장치는 로드셀을 사용하여 발생하는 마찰 토크를 직접 측정하여 마찰손실을 산출하였으며, 마그네틱 커플링을 통해 구동 모터의 동력을 터보과급기 축에 전달하고, 오일 공급 시스템을 오일 온도 및 압력을 조절하였다. 온도 60℃와 90℃, 압력 4bar의 오일을 공급하는 상태에서 터보과급기가 회전수 30,000~90,000rpm으로 작동할 때 터보과급기 회전속도 증가할 때 마찰손실은 증가하며, 대략적으로 과급기 회전속도의 1.4∼1.8 지수승에 비례함을 보이고 있다. 또한 오일온도가 60℃에서 90℃로 증가할 때 마찰손실은 최소 41%, 최대 63% 감소하였다. Turbocharging is widely used in diesel and gasoline engines as an effective way to reduce fuel consumption. But turbochargers have turbo-lag due to mechanical friction losses. Bearing friction losses are a major cause of mechanical friction losses and are particularly intensified in the lower speed range of the engine. Current turbochargers mostly use oil bearings (two journal bearings and one thrust bearing). In this study, we focus on the bearing friction in the lower speed range. Experimental equipment was made using a drive motor, load cell, magnetic coupling, and oil control system. We measured the friction losses of the turbocharger while considering the influence of the rotation speed, oil temperature, and pressure. The friction power losses increased exponentially when the turbocharger speed increased.

다구찌 기법을 이용한 FCM 가스켓의 강건 설계에 관한 연구

정진은(Chung, Jin-Eun),안중규(Ahn, Jueng-Kyu) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.7

본 연구에서는 비석면 FCM(Fiber-elastomer Coated Metal) 가스켓의 강건 설계를 수행하였다. 이를 위하여 직교배열표를 사용한 실험계획법에 따라 전단력을 측정하는 실험을 수행하고 다구찌 기법을 사용하여 망대 SN비를 산출하여 영향을 미치는 제어인자를 파악하고 분산 분석을 수행하였다. 전단력에 영향을 미치는 제어인자로 온도, 압 력, 시간 및 습도를 선택하였으며 각 제어인자에 대하여 3수준을 고려하여 L<sub>9</sub(3⁴)> 직교배열표를 작성하였고, 이에 근거하여 측정 실험을 수행하였다. 다구찌 기법을 사용하여 망대 SN비를 산출하고 델타 통계량을 계산하였다. 시간의 델타 통계량이 0.93으로, 시간이 전단력에 가장 큰 영향을 미치는 결과를 얻었다. 다음으로 온도, 압력, 습도 순으로 영향을 미쳤다. 또한 시간 80초, 온도 200 oC, 압력 90 kgf/cm² 습도 60 %RH의 조건에서 전단력이 최대가 됨을 보 였다. 이에 대한 분산 분석을 수행한 결과 시간과 온도는 각각 p값 0.037, 0.098을 보여 신뢰수준 95%와 90%에서 유 의함을 밝혔다. This paper deals with the robust design of the non-asbestos FCM(Fiber-elastomer Coated Metal) gasket. In order to this, the measurement of the shear stress based on the design of experimet using the orthogonal table was carried out and the control factors for shear stress using the larger-the-better SN ratios with the Taguchi method were evaluated. In addition, the analysis of variance for SN ratios was conducted. The temperature, pressure, duration time and humidity were selected as the control factors. The orthogonal table L<sub>9</sub(3⁴)> was made of 3 levels for each factor and the measurement of shear stress was acomplished on the base of the table. Delta statistics of time is the highest value 0.93 and therefore the time affect the largest effect on the shear stress of gasket. Also from the analysis, the shear stress shows maximun at the duration time 80 sec, temeratue 200 oC, pressure 90 kgf/cm2, humidity 60 %RH. P values of duration time and temperature as a results of the analysis of variance are 0.037 and 0.098. Therefore the analysis has significant each with 95% and 90% confidence level.

소형 디젤엔진용 전자식 EGR 밸브 특성에 관한 연구

정진은(Jin-Eun Chung),진영욱(Youngwook Jin),강우(Woo Kang),정재우(Jae-Woo Chung),강정호(Jeong-Ho Kang) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_1

A test bench which is consisted of blower, heater, air flow meter, driving unit for electric EGR valve, and cooling system for EGR cooler was developed to evaluate the characteristics of the modulated EGR valve. Measurements using EGR valve of the 2.0 L diesel engine were carried out. For this valve, the relation between duty signal and valve lift shows non-linearity and hysteresis phenomenon, and the response time at opening is 84.2 ms. The mass flow rate through the valve is almost zero under 40% duty and is increased according to the duty signal between 40% to 60% duty. For more than 60% duty, the mass flow rate is dependent only the pressure difference. The maximum ratio of the effective area is 0.55. For the over 60% duty the effective area is almost constant and independent of the mass flow rate, but it is decreased as the mass flow rate increases for between 40% and 60% duty. These data will be used to develop the new engine using the modulated EGR and VGT system.

2단 터보과급기 승용 디젤엔진의 성능 시뮬레이션

정진은(Jin-Eun Chung),노호종(Ho-Jong Roh),정재우(Jae-Woo Chung),강우(Woo Kang) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In order to overcome known problems of turbocharged engines, such as, turbo lag and boost threshold, current research is going towards the usage of various combinations of several turbochargers. A good example is the two-stage turbocharged diesel engine. Therefore the research which predicts the performance of two-stage turbocharged diesel engine is carried out. AMESim/IFP Engine Library of Imagine are used for the performance simulation. Specifications and performance maps of turbochargers which are made by some theory and experiments are used. The time constant(63%) of two-stage turbocharged diesel engine when the engine speed is changed from idling to 1500 rpm was 1.2 seconds, which is short 6.9 seconds compared with 8.1 seconds of single-stage engine. This shows the transient response of two-stage turbocharged diesel engine is improved compare with that of the single-stage.

승용차용 터보과급기의 마찰손실 측정에 관한 연구(Ⅰ)

정진은(Jin Eun Chung),이상운(Sang woon Lee),전세훈(Se Hun Jeon),정재우(Jae Woo Chung),김기용(Ji Young Kim) 한국자동차공학회 2016 한국자동차공학회 지부 학술대회 논문집 Vol.2016 No.5

The turbocharger is essential to realize the engine down-sizing. The engine down-sizing with turbocharging is an effective way to reduce engine consumption and become widespread engine performance over the whole operating range. The turbocharger has a turbo-lag due to mechanical friction losses. Current turbocharger is mostly equipped with oil bearings: two journal bearings and one thrust bearing. In this study, we are focused on the bearing friction and the experimental equipment was made using a drive-motor, load-cell, magnetic coupling, thrust-load device and oil control system. This experimental equipment imitated the mainly three parameter that is rotating speed, oil condition and thrust load. Finally, in this study, we developed the device for measuring friction losses of turbocharger as the influence of rotating speed, thrust load, oil temperature and pressure.

승용 디젤엔진 터보과급기의 압축기 성능 예측

정진은(Jin-Eun Chung),정동영(Dong-young Jeong),정재우(Jae-Woo Chung),강우(Woo Kang) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Today, tight and contradictory demands concerning the performance, the exhaust quality and higher milage require the complex system in the engine, such as the combinations of turbochargers. In this engine the control becomes more difficult, Therefore the simple and accurate model for the turbocharger is necessary. This paper deals with the prediction of the compressor performance. The universal curve for flow map and Jenson-Kristensen method for the efficiency map are used. To verify these maps, some measurements were carrying out on the test bench and compared with the results of simulation. As a result of comparison, we can show that the error is inside 5% and it is possible to make 2nd equation compressor performance. Also model using AMESim & IFP engine library is similar to predicted values using universal curve and Jenson-Kristensen method.

가변형 터보과급기의 맥동 유동 성능 측정 시스템 개발

정진은(Jin Eun Chung),진영욱(Youngwook Jin),조훈기(Hungi-Cho),강우(Woo Kang),정재우(Jae Woo Chung) 한국자동차공학회 2007 한국자동차공학회 지부 학술대회 논문집 Vol.- No.-

A test bench which is consisted of roots blower, pulsator, air flow meter, driving unit for VGT actuator, transmitters for temperature and pressure, and the rotational speed sensor was developed to evaluate the characteristics of the VGT system. Measurements using VGT of the 2.0 L diesel engine were carried out. The corrected mass flow rate and the pressure ratio for the compressor of the VGT are related directly with the rotational speed, but they are independent of the rack position of the VGT. The pressure ratio and the corrected mass flow rate of the turbine of the VGT are related directly with the rack position of the VGT, but they don’t have any relation with the rotational speed. The mechanical efficiency of the VGT is higher than the conventional turbocharger in the wide range. The efficiency at the 0.03 kg/s of the mass flow rate is 4.36 times as high as that of the conventional turbocharger. These data will be used to develop the new engine equipped with the VGT system.

[論文] 모델엔진 실린더내의 유동에 대한 다차원 수치해석

정진은(Jin Eun Chung),김응서(Eung Seo Kim) 한국자동차공학회 1989 오토저널 Vol.11 No.3

A multidimensional numerical simulation for flows in an engine with axisymmetric geometry was performed.<br/> Three kinds of differencing schemes, namely, skew upwind differencing scheme (SUDS), interpolated upwind differencing scheme (IUDS), upwind differencing scheme (UDS), are used in a comparative study. Simultaneously, the effects of the artificial dampings and the grids on numerical results are estimated.<br/> Compared with the measurements, the calculations with SUDS and proper artificial damping show very similar qualitative tendency with observed results. But there are some discrepancies due to numerical errors and unclear boundary conditions.