International Conference


TitleHeechang Oh, Choongsik Bae, Jungseo Park, Jeeyeon Jeon, “Effect of the Multiple Injection on Stratified Combustion Characteristics in a Spray-Guided DISI Engine,” SAE Technical Paper 2011-24-0059, presented at 10th SAE International Conference on Engines & Vehicles (ICE 2011) 11-15, September, 2011, Capri, Naples, Italy

Heechang Oh, Choongsik Bae, Jungseo Park, Jeeyeon Jeon, “Effect of the Multiple Injection on Stratified Combustion Characteristics in a Spray-Guided DISI Engine,” SAE Technical Paper 2011-24-0059, presented at 10th SAE International Conference on Engines & Vehicles (ICE 2011) 11-15, September, 2011, Capri, Naples, Italy

Abstract

In this study, the single cylinder engine experiment was carried out to investigate the effect of multiple injections on stratified combustion characteristics in a spray guided direct injection spark ignition engine. The engine was operated at 1200 rpm. The total injection quantity applied was 11 mg/stroke to represent a low-load condition. Single injection and multiple injection were tested. Split ratio of each multiple strategies were 1:1 for double injection and 1:1:1 for the triple injection respectively. Dwell time between each injection was set to 200 µs. In the result of engine experiment with the single injection, indicated mean effective pressure was increased as injection timing was retarded to top dead center due to the increased effective work. However, the retardation of the injection timing was limited by the misfire occurrence resulted from the locally rich mixture generation under the high ambient pressure. Moreover, at the injection timing where the maximum indicated mean effective pressure was shown, hydrocarbon and smoke emissions were increased due to the locally rich area of the stratified mixture. The multiple injection strategy was applied to enhance the local homogeneity of the stratified mixture. In the result of engine experiment with the double injection, indicated mean effective pressure and combustion efficiency were increased. As an index of combustion instability, coefficient variation of indicated mean effective pressure was decreased significantly with the double injection. This result implies that the local homogeneity of the stratified mixture was enhanced by the double injection. Hydrocarbon and carbon monoxide emissions were decreased significantly with the double also. Nitrogen oxides emissions were increased due to the increased in-cylinder temperature resulted by more activated combustion. With the triple injection, the flammable injection timing window became narrower. Furthermore, indicated mean effective pressure and combustion efficiency were decreased. This is likely because the stratified mixture was formed on the upper position of the spark plug due to then shortened spray penetration.

PreviousJeeyeon Jeon, Choongsik Bae, “Effects of EGR and DME Injection Strategy in Hydrogen-DME Compression Ignition Engine,” SAE/JSAE Technical Paper 2011-01-1790, presented at 2011 SAE Powertrains ,Fuel & Lubricants, Kyoto, Aug. 2011
NextJeeyeon Jeon and Choongsik Bae, “Effect of hydrogen and DME injection in homogeneous charge compression ignition engine with DME second injection strategy” IMechE, Internal Combustion Engines: Performance, Fuel Economy and Emissions, London, UK, 29-30 November, 2011

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