Parametric study on the fuel film breakup of a cold start PFI engine

Wang, Y.-P.; Wilkinson, Galen B.; Drallmeier, J. A.

doi:10.1007/s00348-004-0827-x

Cited by 18 publications

(6 citation statements)

References 21 publications

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“…The droplets impingement induced fuel deposits formation on the intake manifold walls. The fuel deposits were drawn by gravity on the valve head where they remained as film due to the surface tension [6,16].…”

Section: Resultsmentioning

confidence: 99%

Optical investigation of the fuel injector influence in a PFI spark ignition engine for two-wheel vehicles

2012

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This paper describes the results obtained in a port fuel injection spark-ignition (PFI SI) engine by optical diagnostics during the fuel injection and the combustion process. A research optical engine was equipped with the fuel injection system, the head and the exhaust device of a commercial 250 cc engine for scooters and small motorcycles. Two injectors were tested: standard 3-hole injector that equipped the real reference engine and a 12-hole injector. The intake manifold was modified to allow the visualization of the fuel injection using an endoscopic system coupled with CCD camera. Size and number of the fuel droplets were evaluated through an image processing procedure. The cycle resolved visualization and chemiluminescence allowed to follow the combustion process from the spark ignition to the exhaust phase. All the optical data were correlated with engine parameters and exhaust emissions. The effect of the fuel injector type on deposits formed by fuel accumulation and dripping on the intake valves steams and seats was investigated. In particular, the evolution of diffusion-controlled flames due to the fuel deposits burning was analyzed. These flames were principally located near the intake valves, and they persisted well after the normal combustion event. The consequences were the formation and emission of soot and unburned hydrocarbons. The multi-hole injector helped reducing wall wetting and deposit formation so that the emission characteristic can be improved. The use of 12-hole injector allowed a more homogeneous distribution for a lower time of fuel droplets in the intake manifold than the 3-hole injector. This study also investigated the detailed physical/chemical phenomena to figure out reasons for the improvement using optical measurements.

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Section: Resultsmentioning

confidence: 99%

Optical investigation of the fuel injector influence in a PFI spark ignition engine for two-wheel vehicles

2012

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“…This assumption is also supported by previous studies. ([13], [14], [7]) Since a line-of-sight effect imposed error on film thickness measurements if determined from the side view, the film thickness was approximated by using a numerical two-phase model presented by [1] rather than experimentally. This 2D numerical model predicted the turbulent air flow field and shear driven liquid film properties, considering the strong interrelated coupling of both phases.…”

Section: High Speed Imaging Techniquementioning

confidence: 99%

“…Different approaches are available in the literature to study the liquid mass separation from a sharp corner for different applications. [1] studied the liquid film separation for a PFI engine by visualization techniques. Engine conditions were simulated by adjusting air flow rate at each valve lift to characterize different separation regimes at the valve seat.…”

Section: Introductionmentioning

confidence: 99%

Mass Separation Regimes for Shear-Driven Liquid Film at Expanding Corners

Sadeghizadeh

Drallmeier

2021

ICLASS

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Separation of gas-driven liquid film from an expanding corner is encountered in many applications such as port fuel injection (PFI) and air-fuel mixing in jet engines. However, physical insight about the liquid mass separation from expanding corners is very limited. Experimental studies show two different flow regimes in shear-driven flows: flow regime where there is no large amplitude waves at the interface and flow regime with large amplitude waves at the interface. Correspondingly liquid mass separation is shown to occur due to two effects: uniform film inertia and large amplitude waves at the interface. In absence of large amplitude waves for large corner angle, the liquid mass separation could occur purely due to uniform film inertia. Two distinct correlations have been proposed for each flow regime based on operating parameters. The controlling parameters, which affect the liquid mass separation at the corner are gas and liquid Reynolds numbers, liquid film properties, and corner angle. Additionally, the proposed correlations would probably need a larger dataset for a robust consistency evaluation.

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“…However, these droplets almost certainly impact downstream on the nozzle walls adhering, bouncing, or shattering. The liquid deposited on to the surface may retain its droplet form or [25][26][27][28][29][30]. Liquid films most probably develop along the pressure side of the nozzle and atomize at the exit of the nozzle (secondary atomization in Fig.…”

Section: Numerical Techniquesmentioning

confidence: 99%

Experimental and numerical study of a spark ignition engine with air-assisted direct injection

Boretti

Jin

Brear

et al. 2008

Proceedings of the Institution of Mechanical Engineers, Part D:

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An experimental and numerical study of the spray from an air-assisted fuel injector in a direct-injection spark ignition (DISI) engine is presented. The experiments are performed using ultraviolet laser diagnostics in a motoring optical engine that is a DISI variant of a production port-fuel-injected engine. Non-optical single-cylinder firing engine results of experiments and simulations are also presented. Recent related work by the present authors has shown that, under design conditions, the air-assisted injector exhibits strong coupling between the liquid and gas phases. It results in a filled-in conical spray of relatively fine atomization and low penetration, with liquid and vapour fuel concentrations close to the centrally located injector and spark plug, as required for lean stratified operation. This paper shows the strong effect of increasing the chamber temperature on spray evaporation and penetration. This observed temperature effect shows that spray evaporation should vary significantly during cold start. Exhaust gas recirculation (EGR) may also have a beneficial effect on DISI engine performance through enhanced spray evaporation, although this is difficult to verify experimentally. If true, this effect of EGR is a separate mechanism to the known beneficial effects of EGR in air-assisted DISI engines

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Parametric study on the fuel film breakup of a cold start PFI engine

Cited by 18 publications

References 21 publications

Optical investigation of the fuel injector influence in a PFI spark ignition engine for two-wheel vehicles

Optical investigation of the fuel injector influence in a PFI spark ignition engine for two-wheel vehicles

Mass Separation Regimes for Shear-Driven Liquid Film at Expanding Corners

Experimental and numerical study of a spark ignition engine with air-assisted direct injection

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