摘要 :
A new Light Stratified-Charge Direct Injection (LSC DI) spark ignition combustion system concept was developed at Ford. One of the new features of the LSC DI concept is to use a "light" stratified-charge operation window ranging f...
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A new Light Stratified-Charge Direct Injection (LSC DI) spark ignition combustion system concept was developed at Ford. One of the new features of the LSC DI concept is to use a "light" stratified-charge operation window ranging from the idle operation to low speed and low load. A dual independent variable cam timing (DiVCT) mechanism is used to increase the internal dilution for emissions control and to improve engine thermal efficiency. The LSC DI concept allows a large relaxation in the requirement for the lean after-treatment system, but still enables significant fuel economy gains over the PFI base design, delivering high technology value to the customer. In addition, the reduced stratified-charge window permits a simple, shallow piston bowl design that not only benefits engine wide-open throttle performance, but also reduces design compromises due to compression ratio, DiVCT range and piston bowl shape constraints. The design, analysis, and experimental testing efforts in developing the combustion system are reported in this paper. A combustion system development methodology was developed and adopted. The methodology features vehicle target cascading, upfront CFD-based design optimization and single-cylinder thermodynamic and optically accessible engine testing for design validation and verification. Application of the methodology allowed a significant reduction of hardware iterations, reducing development time and cost. The LSC DI combustion systems were developed for a family of Ford engines with displacement variants of 0.5, 0.42 and 0.38 liter per cylinder. The systems retained substantial design and component commonality between the DI and PFI variants and among the displacement variants. Significant gains in engine output and fuel economy were demonstrated over the baseline PFI design.
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摘要 :
Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more t...
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Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more than 80% of the hydrocarbon (HC) emissions for the entire EPA FTP75 drive cycle. However, Direct Injection Spark Ignition (DISI) engine cold start optimization is very challenging due to the rapidly changing engine speed, cold thermal environment and low cranking fuel pressure. One approach to reduce HC emissions for DISI engines is to adopt retarded spark so that engines generate high heat fluxes for faster catalyst light-off during the cold idle. This approach typically degrades the engine combustion stability and presents additional challenges to the engine cold start. This paper describes a CFD modeling based approach to address these challenges for the Ford 3.5L V6 EcoBoost engine cold start. A Ford in-house developed CFD code MESIM (Multi-dimensional Engine Simulation) was applied to study the effect of injection parameters and piston designs on the fuel preparation process under various engine speed and engine temperature conditions during the engine crank, run up and cold idle operations. It was found through the modeling studies that the formation of a robust fuel-air mixture distribution around the spark plug was the key to improving combustion stability and reducing the emissions. The factors that could directly affect the fuel-air mixture distribution are the injection timing, fuel pressure, and piston bowl design. Modeling results provided the physical insight of the fuel preparation mechanism of various injection strategies, and helped to optimize the split-injection strategy to improve the fuel-air mixture distribution around the spark plug. The engine test data confirmed that the optimized split injection strategies reduce HC emission by about 30% with lower fuel consumption and substantially improved combustion stability during engine cold-start.
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摘要 :
Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more t...
展开
Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more than 80% of the hydrocarbon (HC) emissions for the entire EPA FTP75 drive cycle. However, Direct Injection Spark Ignition (DISI) engine cold start optimization is very challenging due to the rapidly changing engine speed, cold thermal environment and low cranking fuel pressure. One approach to reduce HC emissions for DISI engines is to adopt retarded spark so that engines generate high heat fluxes for faster catalyst light-off during the cold idle. This approach typically degrades the engine combustion stability and presents additional challenges to the engine cold start. This paper describes a CFD modeling based approach to address these challenges for the Ford 3.5L V6 EcoBoost engine cold start. A Ford in-house developed CFD code MESIM (Multi-dimensional Engine Simulation) was applied to study the effect of injection parameters and piston designs on the fuel preparation process under various engine speed and engine temperature conditions during the engine crank, run up and cold idle operations. It was found through the modeling studies that the formation of a robust fuel-air mixture distribution around the spark plug was the key to improving combustion stability and reducing the emissions. The factors that could directly affect the fuel-air mixture distribution are the injection timing, fuel pressure, and piston bowl design. Modeling results provided the physical insight of the fuel preparation mechanism of various injection strategies, and helped to optimize the split-injection strategy to improve the fuel-air mixture distribution around the spark plug. The engine test data confirmed that the optimized split injection strategies reduce HC emission by about 30% with lower fuel consumption and substantially improved combustion stability during engine cold-start.
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摘要 :
Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more t...
展开
Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more than 80% of the hydrocarbon (HC) emissions for the entire EPA FTP75 drive cycle. However, Direct Injection Spark Ignition (DISI) engine cold start optimization is very challenging due to the rapidly changing engine speed, cold thermal environment and low cranking fuel pressure. One approach to reduce HC emissions for DISI engines is to adopt retarded spark so that engines generate high heat fluxes for faster catalyst light-off during the cold idle. This approach typically degrades the engine combustion stability and presents additional challenges to the engine cold start. This paper describes a CFD modeling-based approach to address these challenges for the Ford 3.5L V6 EcoBoost engine cold start. A Ford in-house developed CFD code MESIM (Multi-dimensional Engine Simulation) was applied to study the effect of injection parameters and piston designs on the fuel preparation process under various engine speed and engine temperature conditions during the engine crank, run up and cold idle operations. It was found through the modeling studies that the formation of a robust fuel-air mixture distribution around the spark plug was the key to improving combustion stability and reducing the emissions. The factors that could directly affect the fuel-air mixture distribution are the injection timing, fuel pressure, and piston bowl design. Modeling results provided the physical insight of the fuel preparation mechanism of various injection strategies, and helped to optimize the split-injection strategy to improve the fuel-air mixture distribution around the spark plug. The engine test data confirmed that the optimized split injection strategies reduce HC emission by about 30% with lower fuel consumption and substantially improved combustion stability during engine cold start.
收起
摘要 :
Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more t...
展开
Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more than 80% of the hydrocarbon (HC) emissions for the entire EPA FTP75 drive cycle. However, Direct Injection Spark Ignition (DISI) engine cold start optimization is very challenging due to the rapidly changing engine speed, cold thermal environment and low cranking fuel pressure. One approach to reduce HC emissions for DISI engines is to adopt retarded spark so that engines generate high heat fluxes for faster catalyst light-off during the cold idle. This approach typically degrades the engine combustion stability and presents additional challenges to the engine cold start. This paper describes a CFD modeling-based approach to address these challenges for the Ford 3.5L V6 EcoBoost engine cold start. A Ford in-house developed CFD code MESIM (Multi-dimensional Engine Simulation) was applied to study the effect of injection parameters and piston designs on the fuel preparation process under various engine speed and engine temperature conditions during the engine crank, run up and cold idle operations. It was found through the modeling studies that the formation of a robust fuel-air mixture distribution around the spark plug was the key to improving combustion stability and reducing the emissions. The factors that could directly affect the fuel-air mixture distribution are the injection timing, fuel pressure, and piston bowl design. Modeling results provided the physical insight of the fuel preparation mechanism of various injection strategies, and helped to optimize the split-injection strategy to improve the fuel-air mixture distribution around the spark plug. The engine test data confirmed that the optimized split injection strategies reduce HC emission by about 30% with lower fuel consumption and substantially improved combustion stability during engine cold start.
收起
摘要 :
Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more t...
展开
Optimization of the engine cold start is critical for gasoline direct injection (GDI) engines to meet increasingly stringent emission regulations, since the emissions during the first 20 seconds of the cold start constitute more than 80% of the hydrocarbon (HC) emissions for the entire EPA FTP75 drive cycle. However, Direct Injection Spark Ignition (DISI) engine cold start optimization is very challenging due to the rapidly changing engine speed, cold thermal environment and low cranking fuel pressure. One approach to reduce HC emissions for DISI engines is to adopt retarded spark so that engines generate high heat fluxes for faster catalyst light-off during the cold idle. This approach typically degrades the engine combustion stability and presents additional challenges to the engine cold start. This paper describes a CFD modeling-based approach to address these challenges for the Ford 3.5L V6 EcoBoost engine cold start. A Ford in-house developed CFD code MESIM (Multi-dimensional Engine Simulation) was applied to study the effect of injection parameters and piston designs on the fuel preparation process under various engine speed and engine temperature conditions during the engine crank, run up and cold idle operations. It was found through the modeling studies that the formation of a robust fuel-air mixture distribution around the spark plug was the key to improving combustion stability and reducing the emissions. The factors that could directly affect the fuel-air mixture distribution are the injection timing, fuel pressure, and piston bowl design. Modeling results provided the physical insight of the fuel preparation mechanism of various injection strategies, and helped to optimize the split-injection strategy to improve the fuel-air mixture distribution around the spark plug. The engine test data confirmed that the optimized split injection strategies reduce HC emission by about 30% with lower fuel consumption and substantially improved combustion stability during engine cold start.
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摘要 :
Recently, Ford Motor Company announced the introduction of EcoBoost engines in its Ford, Lincoln and Mercury vehicles as an affordable fuel-saving option to millions of its customers. The EcoBoost engine is planned to start produc...
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Recently, Ford Motor Company announced the introduction of EcoBoost engines in its Ford, Lincoln and Mercury vehicles as an affordable fuel-saving option to millions of its customers. The EcoBoost engine is planned to start production in June of 2009 in the Lincoln MKS. The EcoBoost engine integrates direct fuel injection with turbocharging to significantly improve fuel economy via engine downsizing. An application of this technology bundle into a 3.5L V6 engine delivers up to 12% better drive cycle fuel economy and 15% lower emissions with comparable torque and power as a 5.4L V8 PFI engine. Combustion system performance is key to the success of the EcoBoost engine. A systematic methodology has been employed to develop the EcoBoost engine combustion system. Instead of a trial-and-error approach, the EcoBoost combustion system development was focused on the fundamental physics with emphasis on the optimization including injector spray pattern, piston geometry, and intake port design, and innovation of operating strategies. The development methodology was led by 3-dimensional CFD modeling together with experiments that used optical, single cylinder, and multi-cylinder engines. As a result, a higher quality design has been achieved through only a few hardware iterations.
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摘要 :
Recently, Ford Motor Company announced the introduction of EcoBoost engines in its Ford, Lincoln and Mercury vehicles as an affordable fuel-saving option to millions of its customers. The EcoBoost engine is planned to start produc...
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Recently, Ford Motor Company announced the introduction of EcoBoost engines in its Ford, Lincoln and Mercury vehicles as an affordable fuel-saving option to millions of its customers. The EcoBoost engine is planned to start production in June of 2009 in the Lincoln MKS. The EcoBoost engine integrates direct fuel injection with turbocharging to significantly improve fuel economy via engine downsizing. An application of this technology bundle into a 3.5L V6 engine delivers up to 12% better drive cycle fuel economy and 15% lower emissions with comparable torque and power as a 5.4L V8 PFI engine. Combustion system performance is key to the success of the EcoBoost engine. A systematic methodology has been employed to develop the EcoBoost engine combustion system. Instead of a trial-and-error approach, the EcoBoost combustion system development was focused on the fundamental physics with emphasis on the optimization including injector spray pattern, piston geometry, and intake port design, and innovation of operating strategies. The development methodology was led by 3-dimensional CFD modeling together with experiments that used optical, single cylinder, and multi-cylinder engines. As a result, a higher quality design has been achieved through only a few hardware iterations.
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摘要 :
Recently, Ford Motor Company announced the introduction of EcoBoost engines in its Ford, Lincoln and Mercury vehicles as an affordable fuel-saving option to millions of its customers. The EcoBoost engine is planned to start produc...
展开
Recently, Ford Motor Company announced the introduction of EcoBoost engines in its Ford, Lincoln and Mercury vehicles as an affordable fuel-saving option to millions of its customers. The EcoBoost engine is planned to start production in June of 2009 in the Lincoln MKS. The EcoBoost engine integrates direct fuel injection with turbocharging to significantly improve fuel economy via engine downsizing. An application of this technology bundle into a 3.5L V6 engine delivers up to 12% better drive cycle fuel economy and 15% lower emissions with comparable torque and power as a 5.4L V8 PFI engine. Combustion system performance is key to the success of the EcoBoost engine. A systematic methodology has been employed to develop the EcoBoost engine combustion system. Instead of a trial-and-error approach, the EcoBoost combustion system development was focused on the fundamental physics with emphasis on the optimization including injector spray pattern, piston geometry, and intake port design, and innovation of operating strategies. The development methodology was led by 3-dimensional CFD modeling together with experiments that used optical, single-cylinder, and multi-cylinder engines. As a result, a higher quality design has been achieved through only a few hardware iterations.
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摘要 :
Recently, Ford Motor Company announced the introduction of EcoBoost engines in its Ford, Lincoln and Mercury vehicles as an affordable fuel-saving option to millions of its customers. The EcoBoost engine is planned to start produc...
展开
Recently, Ford Motor Company announced the introduction of EcoBoost engines in its Ford, Lincoln and Mercury vehicles as an affordable fuel-saving option to millions of its customers. The EcoBoost engine is planned to start production in June of 2009 in the Lincoln MKS. The EcoBoost engine integrates direct fuel injection with turbocharging to significantly improve fuel economy via engine downsizing. An application of this technology bundle into a 3.5L V6 engine delivers up to 12% better drive cycle fuel economy and 15% lower emissions with comparable torque and power as a 5.4L V8 PFI engine. Combustion system performance is key to the success of the EcoBoost engine. A systematic methodology has been employed to develop the EcoBoost engine combustion system. Instead of a trial-and-error approach, the EcoBoost combustion system development was focused on the fundamental physics with emphasis on the optimization including injector spray pattern, piston geometry, and intake port design, and innovation of operating strategies. The development methodology was led by 3-dimensional CFD modeling together with experiments that used optical, single-cylinder, and multi-cylinder engines. As a result, a higher quality design has been achieved through only a few hardware iterations.
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