A Method to Determine Fuel Transport Dynamics Model Parameters in Port Fuel Injected Gasoline Engines During Cold Start and Warm-Up Conditions

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
M. Shahbakhti ◽  
M. Ghafuri ◽  
A. R. Aslani ◽  
A. Sahraeian ◽  
S. A. Jazayeri ◽  
...  
Keyword(s):  
Thermal Conditions ◽  
Cold Start ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
New Method ◽  
Intake Manifold ◽  
Dynamics Model ◽  
Fuel Film ◽  
Warm Up ◽  
Transport Dynamics

In order to meet stringent emission standards, it is essential to have a precise control of air-fuel ratio (AFR) under cold start and warm-up conditions. This requires an understanding of the fuel transport dynamics in the intake system during these conditions. This study centers on estimating the parameters of a fuel transport dynamics model during engine operation at different thermal conditions ranging from cold start to fully warmed-up conditions. A method of system identification based on perturbing fuel injection rate is used to find fuel dynamics parameters in a port fuel injected (PFI) spark ignition engine. Since there was no cold chamber available to prepare cold start conditions, a new method was utilized to simulate cold start conditions. The new method can be applied on PFI engines, which use closed valve injection timing. A four-cylinder PFI engine is tested for different thermal conditions from −15°C to 82°C at a range of engine speeds and intake manifold pressures. A good agreement is observed between simulated and experimental AFR for 52 different transient operating conditions presented in this study. Results indicate that both fuel film deposit factor (X) and fuel film evaporation time constant (τf) decrease with increasing coolant temperature or engine speed. In addition, an increase in the intake manifold pressure results in an increase in X while causes a decrease in τf.

A Novel Method to Estimate Parameters of the Wall-Wetting Fuel Model in MPFI Engines for Cold Start and Warm Up Conditions

2004 ◽  
Author(s):  
M. Shahbakhti ◽  
M. Ghafuri ◽  
A. R. Aslani ◽  
A. Sahraeian ◽  
S. A. Jazayeri ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Cold Start ◽  
Spark Ignition Engine ◽  
Intake Manifold ◽  
Exhaust Emission ◽  
Model Parameters ◽  
Transfer Model ◽  
Fuel Film ◽  
Warm Up ◽  
Fuel Ratio

In order to fulfill the LEV/ULEV exhaust emission standards, it is necessary to have a precise control of air fuel ratio under transient conditions especially during cold start and warm up periods. The objective in this study was to estimate parameters of a fuel delivery model and use them to provide a correct fuel injection compensation strategy. In this study, fuel transfer characteristics of intake port of a typical fuel-injected spark ignition engine have been determined for engine warm-up conditions following cold starts at temperature down to −15°C and extending to fully-warmed-up conditions, using a method based upon perturbing fuel injection rate and recording AFR (Air Fuel Ratio) response. Since there was no cold chamber available to perform tests in cold start conditions, a new method was utilized to simulate cold start conditions. This method can be used on any PFI engine with closed valve injection strategy. Following the estimation of fuel transfer model parameters, the variation of fuel film deposit factor (X), fuel film evaporation time constant (τf) and transport delay to oxygen sensor (ΔT) parameters over a range of temperatures, engine speeds and intake manifold pressures have been evaluated, providing a good insight to define transient fuel compensation requirements for cold start and warm up conditions.

Engine Friction Characteristics Under Cold Start Conditions

2001 ◽  
Author(s):  
Paul J. Shayler ◽  
John A. Burrows ◽  
Clive R. Tindle ◽  
Michael Murphy
Keyword(s):  
Fuel Injection ◽  
Cold Start ◽  
Operating Conditions ◽  
Valve Train ◽  
Bulk Temperature ◽  
Oil Viscosity ◽  
Engine Operation ◽  
Warm Up ◽  
Injection Pump ◽  
Engine Friction

Abstract Most studies of engine friction have been carried out at fully-warm operating conditions. Relatively little attention has been given to frictional losses when the engine is running cold, although these can be considerably higher and have a strong influence both on cold-start characteristics and fuel consumption during warm-up. The losses which effect the indicated load on the engine are rubbing losses and loads associated with driving auxiliaries. The equivalent frictional mean effective pressures (fmep) are generally highest during the first seconds of engine operation. These decay rapidly onto a characteristic variation which depends upon oil viscosity, and which fmep follows throughout the warm-up period. The oil viscosity can be evaluated at the bulk temperature of oil in the sump or main gallery. Breakdown motoring tests have been carried out on a series of diesel engines to examine how the friction contribution of various sub-assemblies in the engine contribute to the total and how this varies with temperature and speed. Tests were carried out using a compact cold cell and engine motoring facility. The engine was cold soaked to a target test temperature and then motored to a target speed and the variation of motoring torque recorded. Sets of tests were carried out at several stages of breaking the engine down. This enables the contributions due to the valve train, piston and big end assembly, crankshaft, fuel injection pump, and auxiliary load to be determined.

A Combined Simulation and Experimental Study on Optimization Intake Manifold of Spark Ignition Engine

2006 ◽  
Author(s):  
Omid Samimi Abiane ◽  
Mostafa Mirsalim ◽  
Mahdi Ahmadi ◽  
Majid Karbasi
Keyword(s):  
Engine Performance ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Intake Manifold ◽  
Performance Parameters ◽  
Engine Simulation ◽  
Basic Engine ◽  
Combined Simulation ◽  
Full Throttle

This paper presents the results of an investigation into the comparison between measured and simulated intake system dynamics of the Peugeot XU7-L3 engine. Simulation and Experimental tests are conducted at full throttle operating conditions ranging from 1500 to 6000 rpm under firing operation. Comparisons of basic engine performance parameters, showed a good correlation between measurement and simulation.

Liquid Film Atomization on Wall Edges—Separation Criterion and Droplets Formation Model

2002 ◽  
Vol 124 (3) ◽  
pp. 565-575 ◽  
Author(s):  
F. Maroteaux ◽  
D. Llory ◽  
J-F. Le Coz ◽  
C. Habchi
Keyword(s):  
Liquid Film ◽  
Fuel Injection ◽  
Liquid Sheet ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Physical Parameters ◽  
Lagrangian Description ◽  
Fuel Film ◽  
Separation Criterion ◽  
Film Separation

In order to predict the fuel mixture preparation inside the cylinder of port fuel injection engines, a model for the aerodynamic stripping of the fuel film deposited on the manifold walls is discussed, and a model for the fuel film separation and atomization near the sharp edges is developed. A separation criterion is set up using an analogy with Rayleigh-Taylor instabilities driven by the inertial forces of the liquid film. To determine the physical parameters of the resulting droplets, a liquid sheet atomization scheme is used. The critical value for the separation criterion is adjusted using experimental data obtained in 2D wind tunnel equipped with different steps shaped as a valve seat, and reproducing the main characteristics of the intake of spark ignition engine. CFD simulations are performed using the KMB code, a modified version of KIVA-2 already including a stochastic Lagrangian description of the spray, and an Eulerian liquid film model. Computations results for different operating conditions are in good agreement with the images of film separation and measured droplet size distributions.

Model-Based Mode Transition Control Between SI and HCCI Combustion

2014 ◽  
Author(s):  
Shupeng Zhang ◽  
Guoming G. Zhu
Keyword(s):  
External Disturbance ◽  
Thermal Conditions ◽  
Spark Ignition Engine ◽  
Intake Manifold ◽  
Mode Transition ◽  
Electronic Throttle ◽  
Engine Torque ◽  
Transition Control ◽  
Hcci Combustion ◽  
Mode Transition Control

While the homogeneous charge compression ignition (HCCI) combustion has its advantages of high thermal efficiency with low emissions, its operational range is limited in both engine speed and load. To utilize the advantage of the HCCI combustion an HCCI capable SI (spark ignition) engine needs to be developed. One of the key challenges of developing such an engine is how to achieve smooth mode transition between SI and HCCI combustion, where the in-cylinder thermal conditions are quite different due to the distinct combustion characteristics. In this paper, an SI-HCCI mode transition control strategy was developed for an HCCI capable SI engine equipped with electrical variable valve timing (EVVT) systems with two step-lift valves and electronic throttle control (ETC) system, and the developed strategy was validated in hardware-in-the-loop (HIL) simulations. During the mode transition, a MAP (manifold air pressure) controller was used to track the desired intake manifold pressure for charge air management, and a fuel management controller is used to provide the desired engine torque. HIL simulation results show that the developed controller is able to achieve smooth combustion mode transition under unmodeled dynamics and external disturbance.

scholarly journals Operating Limits for Ammonia Fuel Spark-Ignition Engine

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4141
Author(s):  
Christine Mounaïm-Rousselle ◽  
Pierre Bréquigny ◽  
Clément Dumand ◽  
Sébastien Houillé
Keyword(s):  
Compression Ratio ◽  
Engine Speed ◽  
Cold Start ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Stable Operation ◽  
Load Limit ◽  
Operating Limits ◽  
A Current

The objective of this paper is to provide new data about the possibility of using ammonia as a carbon-free fuel in a spark-ignition engine. A current GDI PSA engine (Compression Ratio 10.5:1) was chosen in order to update the results available in the literature mainly obtained in the CFR engine. Particular attention was paid to determine the lowest possible load limit when the engine is supplied with pure ammonia or a small amount of H2, depending on engine speed, in order to highlight the limitation during cold start conditions. It can be concluded that this engine can run stably in most of these operating conditions with less than 10% H2 (of the total fuel volume) added to NH3. Measurements of exhaust pollutants, and in particular NOx, have made it possible to evaluate the possibility of diluting the intake gases and its limitation during combustion with pure H2 under slightly supercharged conditions. In conclusion, the 10% dilution limit allows a reduction of up to 40% in NOx while guaranteeing stable operation.

scholarly journals Dual fuelling SI engine with alcohol and gasoline

2011 ◽  
Vol 145 (2) ◽  
pp. 73-81
Author(s):  
Jerzy LARISCH ◽  
Zdzisław STELMASIAK
Keyword(s):  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Thermal State ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Intake Manifold ◽  
Combustion Engines ◽  
Mixing Chamber ◽  
Si Engines ◽  
Dual Fueling

The Department of Internal Combustion Engines and Vehicles, Technical University of Bielsko-Biala has carried out work on alternative fuels in the area of dual-fueling of SI engines. The paper presents the concept of dual fuel (alcohol and gasoline) MPI injected spark-ignition engine using a fuel mixing device. The solution consists in mixing the fuel (gasoline and alcohol) before or in the fuel rail, which ensures a variable share of alcohol in the mixture in the range from 0÷100%, depending on the engine operating conditions (engine revolutions and load), and its thermal state. The fuels are delivered to the mixing chamber through the solenoid valves that allow a proper selection of the proportion of alcohol and gasoline. The pre-prepared mixture is injected through the original injectors to the intake manifold, around the intake valve. This paper presents the prototype of the mixer that allows mixing of the gasoline and alcohol in any proportion using a PWM.

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