A narrow channel setup was established and experiments were conducted to study the pre-ignition characteristics of wire insulation under overload conditions in weak buoyancy environment.The pre-ignition temperature va...A narrow channel setup was established and experiments were conducted to study the pre-ignition characteristics of wire insulation under overload conditions in weak buoyancy environment.The pre-ignition temperature variation trend of both the wire insulation and its nearby temperature monitoring points,the movement characteristics of smoke produced from the wire insulation and the ignition delay time of wire insulation were investigated.The results indicated that the narrow channel setup with a height of 10-15 mm was effective to suppress the effect of buoyancy,and the pre-ignition characteristics of wire insulation in microgravity could be predicted well by the narrow channel method.展开更多
Gasoline direct injection(GDI)engines are currently the dominant powertrains for passenger cars.With the implementation of increasingly stringent fuel consumption and emission regulationsworldwide,GDI engines are faci...Gasoline direct injection(GDI)engines are currently the dominant powertrains for passenger cars.With the implementation of increasingly stringent fuel consumption and emission regulationsworldwide,GDI engines are facing challenges owing to high particulate matter emissions and a tendency to knock,leading to a change in the research and design(R&D)issues compared with those in the twentieth century.This paper reviews the progress in research regarding GDI engine technologies over the past 20 years,focusing on combustion system configurations,and also highlights common issues in GDI R&D,including pre-ignition and deto-knock,soot formation and PM emissions,injector deposits and gasoline compression ignition(GCI).First,an overview of recent developments in the field as driven by regulations is provided,following which progress in injection and combustion systems is examined.Third,the review addresses the occurrence and mechanism of deto-knock and considers means of suppressing this phenomenon.The fourth section discusses soot formation mechanisms and particulate matter emission characteristics of GDI engines and describes the application of gasoline particulate filter(GPF)after-treatment.The subsequent section summarizes studies regarding injector deposit formation,as well as pioneering research into GCI combustion modes.Finally,a summary and future prospects for GDI engine technologies are provided.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 50976115)the Pilot Special Programs of Chinese Academy of Sciences (Grant Nos. XDA04020208 and XDA04073202)
文摘A narrow channel setup was established and experiments were conducted to study the pre-ignition characteristics of wire insulation under overload conditions in weak buoyancy environment.The pre-ignition temperature variation trend of both the wire insulation and its nearby temperature monitoring points,the movement characteristics of smoke produced from the wire insulation and the ignition delay time of wire insulation were investigated.The results indicated that the narrow channel setup with a height of 10-15 mm was effective to suppress the effect of buoyancy,and the pre-ignition characteristics of wire insulation in microgravity could be predicted well by the narrow channel method.
基金The authors acknowledge theChina NationalNat-ural Science Foundation Project“Formation and Evolution of PM from GDI Engines:From Primary Particles to Secondary Aerosols”(Grant No.51636003)the National Key R&D Plan Project“Integration Technology of PM Capture and Clean Emissions for GDI Vehicles”(Grant No.2017YFC02110004).
文摘Gasoline direct injection(GDI)engines are currently the dominant powertrains for passenger cars.With the implementation of increasingly stringent fuel consumption and emission regulationsworldwide,GDI engines are facing challenges owing to high particulate matter emissions and a tendency to knock,leading to a change in the research and design(R&D)issues compared with those in the twentieth century.This paper reviews the progress in research regarding GDI engine technologies over the past 20 years,focusing on combustion system configurations,and also highlights common issues in GDI R&D,including pre-ignition and deto-knock,soot formation and PM emissions,injector deposits and gasoline compression ignition(GCI).First,an overview of recent developments in the field as driven by regulations is provided,following which progress in injection and combustion systems is examined.Third,the review addresses the occurrence and mechanism of deto-knock and considers means of suppressing this phenomenon.The fourth section discusses soot formation mechanisms and particulate matter emission characteristics of GDI engines and describes the application of gasoline particulate filter(GPF)after-treatment.The subsequent section summarizes studies regarding injector deposit formation,as well as pioneering research into GCI combustion modes.Finally,a summary and future prospects for GDI engine technologies are provided.
