• 한국자동차공학회논문집
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• 제12권3호
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• pp.44-50
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• 2004

The purpose of this study is to improve the prediction ability of the atomization and vaporization processes of GDI spray under high-pressure and high-temperature conditions. Several models have been introduced and compared. The atomization process was modeled using hybrid breakup model that is composed of Conical Sheet Disintegration (CSD) model and Aerodynamically Progressed TAB(APTAB) model. The vaporization process was modeled using Spalding model, modified Spalding model and Abramzon ＆ Sirignano model. Exciplex fluorescence method was used for comparing the calculated with the experimental results. The experiment and calculation were performed at the ambient pressure of 0.5 MPa and 1.0 MPa and the ambient temperature of 473k. Comparison of caldulated and experimental spray characteristics was carried out and Abramzon ＆ Sirignano model and modified Spalding model had the better prediction ability for vaporization process than Spalding model.

• 한국분무공학회지
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• 제20권3호
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• pp.156-161
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• 2015

This paper described the effect of dual clutch transmissions on the stability emissions characteristic in a GDI engine at vehicle Inspection and Maintenance(I/M) program. In order to investigate the influence of direct injection gasoline engine with DCT, the experimental apparatus consisted of GDI engine with 4 cylinder, dynamometer and exhaust emissions analyzer. Analyzed emission gas include CO, HC and NOx results that DCT vehicle in the case of NOx, HC in automatic transmission vehicles less than 1/2 level was confirmed to be exhausted. However vehicle specific power increases CO also has increased.

• 한국분무공학회지
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• 제25권2호
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• pp.51-59
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• 2020

The purpose of this study is to propose and compare methods for measuring individual spray cone angles using spray cross-section images. In direct injection gasoline engines, it was believed that the distribution of air-fuel mixture in the combustion chamber directly affected combustion performance and emission formation. However, since gasoline direct injection (GDI) injectors have a small injection angle, interference between individual spray plumes occurs. Therefore, GDI injectors have only measured the spray angle of the entire spray. To overcome these limitations, three methods of indirectly measuring the spray cone angles of individual spray plume were presented and compared by forming sheet beams using Nd:YAG laser and acquiring spray cross-section images. Each method currently has advantages and disadvantages, and research to apply the method suitable for various GDI injectors needs to be continued.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.466-471
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• 2003

The purpose of this study is to obtain the accurate prediction for the atomization and vaporization processes of GDI spray. Atomization process is modeled using hybrid model that is composed of Linearized Instability Sheet Atomization (LISA) model and Aerodynamically Progressed TAB (APTAB) model. Vaporization process is modeled using Spalding model and Abramzon & Sirignano model. To obtain the experimental results for comparing with calculated results, the cross-sectional images of liquid and vapor phases and SMD distribution were acquired by exciplex fluorescence method and Phase Doppler Analyzer respectively. The experiment and computation was performed at the ambient pressure of 0.1 MPa, 0.5 MPa, 1.0 MPa and the ambient temperature of 293K, 473K. The calculated results by modified KIVA-II code show good agreement with experimental results.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.50-58
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• 2001

The purpose of this research is to obtain the information of the development process of a vaporizing GDI spray using exciplex fluorecence method. Fluorobenzene/DEMA system was used as the exciplex-forming dopants. The 2-D spray images of liquid and vapor phases were acquired, and the behavior of both phases was analyzed by the image processing. The experiment was performed at the three different ambient perssures and the ambient temperature of 273K and 473K. As the result of this work, it was found that the development characteristics of GDI spray have stronger effect on the ambient pressure than on the ambient temperature. With an increase of ambient pressure, the distribution of vapor phase was decreased and the concentration of that was denser. Two regions, namely cone and mixing regions could be identified from those resulrs.

• 한국자동차공학회논문집
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• 제13권6호
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• pp.187-194
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• 2005

The objective of this study is to validate the hybrid breakup model and the vaporization model for GDI spray analysis at vaporization and non-vaporization conditions. The atomization process is modeled by using hybrid breakup model that is composed of Linearized Instability Sheet Atomization (LISA) model and Aerodynamically Progressed Taylor Analogy Breakup (APTAB) model. The vaporization process is modeled by using modified Abramzon & Sirignano model. The exciplex fluorescence method was used for comparing the calculated results with the experimental ones. The experiment and the calculation were performed at the ambient pressures of 0.1 MPa, 0.5 MPa and 1.0 MPa and the ambient temperature of 293K and 473K.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.171-172
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• 2014

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.23.2-23.2
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• 2007

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• 대한기계학회논문집B
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• 제39권4호
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• pp.351-358
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• 2015

세계적인 배출가스 규제의 강화와 함께 화석 연료의 매장량 감소와 유가 상승은 새로운 엔진 기술 개발을 촉진시켰다. 가솔린 직접 분사(GDI; Gasoline Direct Injection) 엔진은 연료를 직접 연소실에 공급하고 정밀한 연소제어를 통해 공연비가 희박한 혼합 상태에서도 연소가 가능하게 하였는데, 이러한 방식은 기존 포트 분사 엔진보다 연비와 출력을 모두 향상시킬 수 있다. 하지만 GDI엔진은 디젤 엔진의 경우와 마찬가지로 soot 발생률이 높아짐에 따라 입자상 물질의 배출이 증대되는 문제를 안고 있다. 이러한 문제를 해소하고자 본 연구에서는 가솔린 입자상 물질 필터(GPF; Gasoline Particulate Filter)를 개발하여 입자상 물질의 배출정도를 저감시키고자 하였다. 필터의 설계 효율에 따라 3가지의 Metal foam 필터와 단일 Metal fiber 필터를 실험에 적용하여 PM과 PN의 저감률을 비교하였다.

• 한국소음진동공학회논문집
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• 제22권10호
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• pp.985-993
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• 2012

In this paper, a new method is proposed to estimate the sound pressure generated from gasoline direct injection (GDI) engine. There are many noise sources as much as components in GDI engine. Among these components, fuel pump, fuel injector, fuel rail, pressure pump and intake/exhaust manifolds are major components generated from top of the engine. In order to estimate the contribution of these components to engine noise, the total sound pressure at the front of the engine is estimated by using airborne source quantification (ASQ) method. Airborne source quantification method requires the acoustic source volume velocity of each component. The volume velocity has been calculated by using the inverse method. The inverse method requires many tests and has ill-condition problem. This paper suggested a method to obtain volume velocity directly based on the direct measurement of sound intensity and particle velocity. The method is validated by using two known monopole sources installed at the anechoic chamber. Finally the proposed method is applied to the identification and contribution of noise sources caused by the GDI components of the test engine.