Experimental investigation in an optically accessible diesel engine of a fouled piezoelectric injector

Magno, Agnese; Mancaruso, Ezio; Vaglieco, Bianca Maria

doi:10.1016/j.energy.2013.10.071

Cited by 23 publications

(13 citation statements)

References 35 publications

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“…Over the last three decades, performance, fuel consumption and exhaust emissions have been significantly improved. Nonetheless, increasing concerns in pollutant emissions demand a critical and detailed evaluation of the combustion process, which is largely influenced by fuel-air mixing (Ma et al, 2014;Magno et al, 2014). To this end, computational fluid dynamic (CFD) models offer unmatched advantages over the experimental approach due to the large amount of detailed and localized information they are able to provide.…”

Section: Introductionmentioning

confidence: 99%

Experimental Analysis on the Influence of Nozzle Geometry Over the Dispersion of Liquid N-Dodecane Sprays

2015

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Understanding and controlling mixing and combustion processes is fundamental in order to face the challenges set by the ever more demanding pollutant regulations and fuel consumption standards of direct injection diesel engines. The fundamentals of these processes haven been long studied by the diesel spray community from both experimental and numerical perspectives. However, certain topics, such as the influence of nozzle geometry over the spray atomization, mixing, and combustion process, are still not completely well understood and predicted by numerical models. The present study seeks to contribute to the current understanding of this subject, by performing state of the art optical diagnostics to liquid sprays injected through two singe-hole nozzles of different conicity. The experiments were carried out in a nitrogen-filled constantpressure-flow facility. Back pressures were set to produce the desired engine-like density conditions in the chamber, at room temperature. The experimental setup consists in a diffused back-illumination setup with a fast pulsed LED light source and a high-speed camera. The diagnostics focused on detecting the liquid spray contour and evaluating the influence of nozzle geometry over the time-resolved and quasi-steady response of the spray dispersion, at similar injection conditions. Results show a clear influence of nozzle geometry on spray contour fluctuations, where the cylindrical nozzle seems to produce larger dispersion in both time-resolved fluctuations and quasi-steady values, when compared to the conical nozzle. This evidences that the turbulence and radial velocity profiles originated at the cylindrical nozzle geometry are able to affect not only the microscopic scales inside the nozzle, but also macroscopic scales, such as the steady spray. Observations from this study indicate that the effects of the flow characteristics within the nozzle are carried on to the first millimeters of the spray, in which the rest of the spray formation downstream is pre-defined.

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Section: Introductionmentioning

confidence: 99%

Experimental Analysis on the Influence of Nozzle Geometry Over the Dispersion of Liquid N-Dodecane Sprays

2015

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“…This allows high enough injection pressure to be used even in low-end torque area, which is good to satisfy the varied demands at different engine conditions. 1,4,5 The rail pressure level in CR systems can be controlled by means of two main strategies. 6 In both of them, a pressure sensor monitors the rail pressure and the difference between nominal and measured rail pressure is the input signal for a proportional–integral–derivative (PID) controller.…”

Section: Introductionmentioning

confidence: 99%

“…The high injection pressures greatly influence fuel spray, combustion and diesel engine output power and emissions under both steady state and transient conditions. [1][2][3] Furthermore, the fuel pressure in this injection apparatus has little direct relationship with the engine speed since the high-pressure pump continuously delivers high-pressure fuel, which is stored in the rail. This allows high enough injection pressure to be used even in low-end torque area, which is good to satisfy the varied demands at different engine conditions.…”

Section: Introductionmentioning

confidence: 99%

Instantaneous torque, energy saving and flow rate ripple analysis of a common rail pump equipped with different delivery-pressure control systems

Ferrari

Vitali

2017

International Journal of Engine Research

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A mechanical model of a high-pressure pump of a common rail fuel injection system is presented and validated by comparison with experimental instantaneous pump shaft torque and pump piston lift data. The instantaneous torque has been measured with a high-performance torque meter installed on a hydraulic rig for testing pieces of injection apparatus. In the model, the mechanics of the piston plunger and the forces exchanged between pistons and cam are simulated, and friction losses between mobile parts are taken into account. The numerical tool is used to investigate the dynamical performance of the high-pressure pump and to analyse the impact of the rail pressure control strategy on instantaneous torque, energy saving and flow rate ripple. The rail pressure control strategy, based on the application of a fuel metering valve at the pump inlet, gives rise to an improved hydraulic efficiency of the injection system at part loads and to a moderate rate of pressure increase in the pumping chamber at part loads. However, the rail pressure control strategy based on the installation of a pressure control valve at one rail extremity leads to a reduction in the pump flow rate ripple and to a diminution in the fatigue stress. Furthermore, cavitation problems can occur during intake and early compression phases of the pump cycle when the fuel metering unit is working.

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“…The first kind is the common rail direction injection (CRDI) system, which makes the fuel pressure have little direct relationship with the engine speed as the high-pressure fuel is reserved in the rail. 13,14 However, the CRDI system is not widely used in many countries due to the poor fuel quality there. Thus, as an alternative, the electronic unit pump (EUP) system, which has a low requirement on the fuel quality and is easier to be machined, 15 is more often equipped on the engine in these countries.…”

Section: Introductionmentioning

confidence: 99%

Effects of fuel temperature on injection performance of an EUP system

Liu

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part D:

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The fuel temperature has a great influence on the characteristics of an electronic unit pump (EUP) system, especially on the injection performance. This paper studies the regularity of the high-pressure fuel supply system performance at different fuel temperatures. The injection quantity, the injection rate, the fuel pressure, and the needle lift were measured by the EUP system test bench. Investigation results showed that, with the increase of fuel temperature, the injection quantity and maximum injection rate decreased, the time of start injection was delayed, and the peak fuel pressure value decreased. For the needle valve, as the temperature was raised its closing time was advanced at low speed conditions but delayed at high speed conditions. In addition, the empirical equations for the fuel temperature effects on the circulating fuel injection quantity and peak pressure are proposed by the experimental test and simulation data. This study will help to further apply and study the engine, and provide a reference for engine fuel supply control system design.

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Experimental investigation in an optically accessible diesel engine of a fouled piezoelectric injector

Cited by 23 publications

References 35 publications

Experimental Analysis on the Influence of Nozzle Geometry Over the Dispersion of Liquid N-Dodecane Sprays

Experimental Analysis on the Influence of Nozzle Geometry Over the Dispersion of Liquid N-Dodecane Sprays

Instantaneous torque, energy saving and flow rate ripple analysis of a common rail pump equipped with different delivery-pressure control systems

Effects of fuel temperature on injection performance of an EUP system

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