Post Fuel Injection Fuel Vaporization Characteristics in the Intake Port of a Port-Fuel-Injected Gasoline CFR Engine

2006 ◽  
Author(s):  
Jim S. Cowart ◽  
Leonard J. Hamilton
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Fuel Vapor ◽  
Intake Port ◽  
Fuel Injector ◽  
Intake Valve ◽  
Inlet Port ◽  
Fuel Vaporization ◽  
Control Computer ◽  
Vapor Sampling

A Cooperative Fuels Research (CFR) gasoline engine has been modified to run on computer controlled Port Fuel Injection (PFI) and electronic ignition. Additionally a fast acting sampling valve (controlled by the engine control computer) has been placed in the engine’s intake system between the fuel injector and cylinder head in order to measure the fuel components that are vaporizing in the intake port immediately after the fuel injection event, and separately during the intake valve open period. This is accomplished by fast sampling a small portion of the intake port gases during a specified portion of the engine cycle which are then analyzed with a gas chromatograph. Experimental mixture preparation results as a function of inlet port temperature and pressure are presented. As the inlet port operates at higher temperatures and lower manifold pressures more of the injected fuels’ heavier components evolve into the vapor form immediately after fuel injection. The post-fuel injection fuel-air equivalence ratio in the intake port is characterized. The role of the fuel injection event is to produce from 1/4 to slightly over 1/2 of the combustible fuel-air mixture needed by the engine, as a function of port temperature. Fuel vapor sampling during the intake valve open period suggests that very little fuel is vaporizing from the intake port puddle below the fuel injector. In-cylinder fuel vapor sampling shows that significant fuel vapor generation must occur in the lower intake port and intake valve region.

Modeling of Gas Turbine Fuel Nozzle Spray

1997 ◽  
Vol 119 (1) ◽  
pp. 34-44 ◽  
Author(s):  
N. K. Rizk ◽  
J. S. Chin ◽  
M. K. Razdan
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
Near Field ◽  
Continuous Phase ◽  
Liquid Sheet ◽  
Vapor Concentration ◽  
Fuel Vapor ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Sheet Breakup

Satisfactory performance of the gas turbine combustor relies on the careful design of various components, particularly the fuel injector. It is, therefore, essential to establish a fundamental basis for fuel injection modeling that involves various atomization processes. A two-dimensional fuel injection model has been formulated to simulate the airflow within and downstream of the atomizer and address the formation and breakup of the liquid sheet formed at the atomizer exit. The sheet breakup under the effects of airblast, fuel pressure, or the combined atomization mode of the airassist type is considered in the calculation. The model accounts for secondary breakup of drops and the stochastic Lagrangian treatment of spray. The calculation of spray evaporation addresses both droplet heat-up and steady-state mechanisms, and fuel vapor concentration is based on the partial pressure concept. An enhanced evaporation model has been developed that accounts for multicomponent, finite mass diffusivity and conductivity effects, and addresses near-critical evaporation. The presents investigation involved predictions of flow and spray characteristics of two distinctively different fuel atomizers under both nonreacting and reacting conditions. The predictions of the continuous phase velocity components and the spray mean drop sizes agree well with the detailed measurements obtained for the two atomizers, which indicates the model accounts for key aspects of atomization. The model also provides insight into ligament formation and breakup at the atomizer exit and the initial drop sizes formed in the atomizer near field region where measurements are difficult to obtain. The calculations of the reacting spray show the fuel-rich region occupied most of the spray volume with two-peak radial gas temperature profiles. The results also provided local concentrations of unburned hydrocarbon (UHC) and carbon monoxide (CO) in atomizer flowfield, information that could support the effort to reduce emission levels of gas turbine combustors.

Reduction of Nitric Oxide Emission From a SI Engine by Water Injection at the Intake Runner

2009 ◽  
Author(s):  
Jun-Kai Wang ◽  
Jing-Lun Li ◽  
Ming-Hsun Wu ◽  
Rong-Horng Chen
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Effective Means ◽  
Water Injection ◽  
Nox Emission ◽  
Injection System ◽  
Hydrocarbon Emissions ◽  
Fuel Injector ◽  
Unburned Hydrocarbon ◽  
Nitric Oxide Emission

The effects of pulsed water injection at the intake port of a modern port fuel injection gasoline engine were investigated. A port water injection system was developed and the water injector was installed on the intake runner of the single cylinder motorcycle engine at a location upstream of the fuel injector. The results show that with a water-gasoline injection ratio of 1, more than 80% of NOx emission can be removed. The trade-off was a 25% reduction in torque output at 4000 rpm and 20% throttle opening; however, the decrease on torque can be controlled to be within 5% by reducing water-gasoline mass ratios to less than 0.6. We also performed NOx emission modeling using one-dimensional gas dynamics code with extended Zeldovich mechanism, and consistent results were found between numerical prediction and experimental measurements. The port water injection approach appears to be an effective means for reducing NOx emission from a gasoline engine at low speed and high load conditions without largely sacrificing the performances on torque output and unburned hydrocarbon emissions.

Understanding the infiuence of valve timings on controlled autoignition combustion in a four-stroke port fuel injection engine

2005 ◽  
Vol 219 (6) ◽  
pp. 807-823 ◽  
Author(s):  
Li Cao ◽  
Hua Zhao ◽  
Xi Jiang ◽  
Navin Kalian
Keyword(s):  
Gas Exchange ◽  
Gasoline Engine ◽  
Fuel Injection ◽  
Exchange Process ◽  
Combustion Process ◽  
Intake Valve ◽  
Time Model ◽  
Port Fuel Injection ◽  
Cycle Simulation ◽  
Controlled Autoignition

Controlled autoignition (CAI) combustion, also known as homogeneous charge compression ignition (HCCI), was achieved through the negative valve overlap approach by using small- lift camshafts. Three-dimensional multicycle engine simulations were carried out in order better to understand the effects of variable intake valve timings on the gas exchange process, mixing quality, CAI combustion, and pollutant formation in a four-stroke port fuel injection (PFI) gasoline engine. Full engine cycle simulation, including complete gas exchange and combustion processes, was carried out over several cycles in order to obtain the stable cycle for analysis. The combustion models used in the present study are a modified shell ignition model and a laminar and turbulent characteristic time model, which can take high residual gas fraction into account. After the validation of the model against experimental data, investigations of the effects of variable intake valve timing strategies on the CAI combustion process were carried out. These analyses show that the intake valve opening (IVO) and intake valve closing (IVC) timings have a strong infiuence on the gas exchange and mixing processes in the cylinder, which in turn affect the engine performance and emissions. Symmetric IVO timing relative to exhaust valve closing (EVC) timing tends to produce a more stratified mixture, earlier ignition timing, and localized combustion, and hence higher NO x and lower unburned HC and CO emissions, whereas retarded IVO leads to faster mixing, a more homogeneous mixture, and uniform temperature distribution.

Experimental and Theoretical Study of Injection Timing on Performance and Exhaust Emissions in a Port-Injected Gasoline Engine

2006 ◽  
Author(s):  
E. Movahednejad ◽  
F. Ommi ◽  
M. Hosseinalipour ◽  
O. Samimi
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Engine Performance ◽  
Fuel Mixture ◽  
Exhaust Emissions ◽  
Operating Conditions ◽  
Exhaust Emission ◽  
Injection Timing ◽  
Intake Port ◽  
One Dimensional

For spark ignition engines, the fuel-air mixture preparation process is known to have a significant influence on engine performance and exhaust emissions. In this paper, an experimental study is made to characterize the spray characteristics of an injector with multi-disc nozzle used in the engine. The distributions of the droplet size and velocity and volume flux were characterized by a PDA system. Also a model of a 4 cylinder multi-point fuel injection engine was prepared using a fluid dynamics code. By this code one-dimensional, unsteady, multiphase flow in the intake port has been modeled to study the mixture formation process in the intake port. Also, one-dimensional air flow and wall fuel film flow and a two-dimensional fuel droplet flow have been modeled, including the effects of in-cylinder mixture back flows into the port. The accuracy of model was verified using experimental results of the engine testing showing good agreement between the model and the real engine. As a result, predictions are obtained that provide a detailed picture of the air-fuel mixture properties along the intake port. A comparison was made on engine performance and exhaust emission in different fuel injection timing for 2600 rpm and different loads. According to the present investigation, optimum injection timing for different engine operating conditions was found.

Modeling of Gas Turbine Fuel Nozzle Spray

1995 ◽  
Author(s):  
N. K. Rizk ◽  
J. S. Chin ◽  
M. K. Razdan
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
Near Field ◽  
Continuous Phase ◽  
Liquid Sheet ◽  
Vapor Concentration ◽  
Fuel Vapor ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Sheet Breakup

Satisfactory performance of the gas turbine combustor relies on the careful design of various components, particularly the fuel injector. It is, therefore, essential to establish a fundamental basis for fuel injection modeling that involves various atomization processes. A 2-D fuel injection model has been formulated to simulate the airflow within and downstream of the atomizer and address the formation and breakup of the liquid sheet formed at the atomizer exit. The sheet breakup under the effects of airblast, fuel pressure, or the combined atomization mode of the air-assist type is considered in the calculation. The model accounts for secondary breakup of drops and the stochastic Lagrangian treatment of spray. The calculation of spray evaporation addresses both droplet heat-up and steady-state mechanisms, and fuel vapor concentration is based on partial pressure concept. An enhanced evaporation model has been developed that accounts for multicomponent, finite mass diffusivity and conductivity effects, and addresses near critical evaporation. The present investigation involved predictions of flow and spray characteristics of two distinctively different fuel atomizers under both nonreacting and reacting conditions. The predictions of the continuous phase velocity components and the spray mean drop sizes agree well with the detailed measurements obtained for the two atomizers, which indicates the model accounts for key aspects of atomization. The model also provides insight into ligament formation and breakup at the atomizer exit and the initial drop sizes formed in the atomizer near field region where measurements are difficult to obtain. The calculations of the reacting spray show the fuel rich region occupied most of the spray volume with two-peak radial gas temperature profiles. The results also provided local concentrations of unburned hydrocarbon (UHC) and carbon monoxide (CO) in atomizer flowfield, information that could support the effort to reduce emission levels of gas turbine combustors.

Measurements of in-cylinder mixture strength and fuel accumulation in the inlet port of a gasoline - injected engine during very rapid throttle openings

1998 ◽  
Vol 212 (2) ◽  
pp. 103-118 ◽  
Author(s):  
N Ladommatos ◽  
D Rose
Keyword(s):  
Engine Speed ◽  
Gasoline Engine ◽  
Fuel Injection ◽  
Spark Ignition Engine ◽  
Fuel Injectors ◽  
Inlet Port ◽  
Fuel Ratio ◽  
Fuel Accumulation ◽  
Engine Coolant ◽  
Three Way Catalyst

The mixture strength in a cylinder of a port-injected gasoline engine was monitored continuously during very rapid throttle openings. The data on mixture strength were combined with other engine data collected in order to obtain for each successive engine cycle: the air—fuel ratio within the cylinder and the change in the fuel mass accumulating on the inlet port of the cylinder being monitored. The four-cylinder spark-ignition engine used had a displacement of 1.6 litre, four valves per cylinder and multipoint sequential fuel injection controlled by an electronic management system programmed for three - way catalyst operation. All tests were conducted with the engine coolant at the temperature of 90°C and at a constant engine speed of 2000 r/min. The engine transient involved very rapid throttle openings which were completed within about 15 ms. Small and large throttle openings were investigated along with the effect of altering the type and condition of the fuel injectors. The engine response to the fast throttle opening comprised a sharp rise in the air—fuel ratio (maximum gravimetric air—fuel ratio of around 25:1) which lasted for only a single cycle, followed by a drop in the air-fuel ratio (minimum air—fuel ratio of about 10:1) and, subsequently, a gradual rise towards a stoichiometric air—fuel ratio within about 10 engine cycles.

Effect of intake swirl on combustion performance in an unthrottled spark ignition engine

2018 ◽  
Vol 233 (5) ◽  
pp. 1269-1279
Author(s):  
Kaiyu Zhang ◽  
Yingjie Chang ◽  
Zongfa Xie ◽  
Tingting Sun ◽  
Fei Chen
Keyword(s):  
Combustion Rate ◽  
Fuel Injection ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Valve Lift ◽  
Intake Port ◽  
Intake Valve ◽  
Port Fuel Injection ◽  
Air Mixing ◽  
Intake Swirl

A Fully Hydraulic Variable Valve System is described in this article which can achieve continuous variation in valve lift, duration, and timing. The system was installed in a four-cylinder port fuel injection spark ignition engine and achieved unthrottled load control through early intake valve closing. The in-cylinder pressure measured experimentally showed that pumping losses of the unthrottled spark ignition engine at 2000 r/min and 0.189 MPa brake mean effective pressure was reduced by 85.4% compared with the throttled spark ignition engine. However, its slow and unstable combustion reduced the indicated thermal efficiency. Compared with the throttled spark ignition engine, the amount of residual exhaust flowing back into the intake port was greatly reduced at the early stage of the intake process. Consequently, it negatively influenced fuel evaporation and fuel–air mixing processes in the intake port of the port fuel injection spark ignition engine and decreased the flow of in-cylinder gases, which resulted in a low combustion rate. A new centrosymmetric helical valve is proposed in this article to improve the fuel–air mixing and combustion rate of the unthrottled spark ignition engine. The experiments demonstrate that the helical valve can generate a strong intake swirl at small intake valve lift. It helps to increase combustion rate and lower cycle-to-cycle variation, which improves indicated thermal efficiency and fuel economy of the unthrottled spark ignition engine at low load.

scholarly journals Experimental study on particulate control of turbo gasoline engine

2021 ◽  
Vol 268 ◽  
pp. 01014
Author(s):  
Shicheng Li ◽  
Kongwu Chen ◽  
Yongsheng Long ◽  
Hao Peng ◽  
Jingbo Wang ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Particulate Filter ◽  
Particulate Emissions ◽  
Fuel Injector ◽  
Passenger Vehicles ◽  
Object Based ◽  
Particulate Control ◽  
Shift Point ◽  
The Cost

This study takes light-passenger vehicles with 1.5L port fuel injection turbocharged engine as the research object, based on the WLTC test cycle about the China 6b emissions regulations, including some influence of several key technologies, such as fuel injector selection, intake VVT opening, fuel control and gear shift point matching, what can affect the particulate emissions from light-passenger vehicles. The results show that without particulate filter (GPF) technology, Using the original 4-hole fuel injector, the opened intake air VVT in catalyst light off, the optimized fuel control and gearbox shift point, the emission test results of the light-passenger vehicle can reach the development target of China 6b, what can avoid GPF blockage and regeneration problems in the market. Meanwhile, the cost of mass production and development cycle about vehicle is effectively reduced.

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