Microscopic spray characteristics of ethanol and methanol blended gasoline in a direct injection spark ignition engine

2021 ◽  
pp. 146808742098776
Author(s):  
Nikhil Sharma ◽  
Avinash Kumar Agarwal

Renewable fuels are continuously being refined/ upgraded for automotive applications to reduce dependence on conventional fossil fuels. However, optimized use of these renewable fuels in existing and new engines/ vehicles requires comprehensive characterization and understanding of spray atomization and fuel-air mixture formation processes. Spray atomization and mixture formation depends on fuel injection pressure (FIP), fuel injection quantity and ambient conditions. This study is aimed at exploring microscopic spray characteristics of ethanol and methanol blended gasoline for automotive applications, particularly in direct injection Spark Ignition (DISI) engines. Phase Doppler interferometer (PDI) technique was used for comparative microscopic spray characterization in a constant volume spray chamber (CVSC) at ambient pressure condition, to evaluated spray droplet size-velocity distributions and joint probability density function (JPDF) of different test fuels. In this study, two gasohol mixtures [15% v/v ethanol and methanol blended with 85% v/v gasoline] and baseline gasoline were experimentally evaluated for comparing spray droplet size-velocity distributions at two different FIPs of 80 and 160 bars, at two different fuel injection quantities of 12 and 28 mg/injection, which are typical representative conditions for a DISI engines. The results from this experimental investigation are valuable for automotive and fuel industries, and spray community, which are continuously upgrading renewable and oxygenated fuels and engine technologies for efficiency improvement and emission reduction.

2019 ◽  
Vol 21 (4) ◽  
pp. 664-682
Author(s):  
Martin Theile ◽  
Martin Reißig ◽  
Egon Hassel ◽  
Dominique Thévenin ◽  
Martin Hofer ◽  
...  

This work summarizes the numerical analysis of the effect of early fuel injection on the charge motion in a direct injection spark ignition engine concerning cyclic fluctuations of the flow field. The combination of the scale-resolving turbulence model “Scale Adaptive Simulation” and post-processing routines for vortex trajectory visualization allows for a detailed insight into the temporal resolved and cycle-dependent behavior of the charge motion. In the first part, a simplified engine set-up is presented and used as a validation case to ensure correct behavior of the turbulence model and post-processing routines. In the second part, the computational fluid dynamics model of the real engine is introduced. The application of the proposed vortex tracking algorithm is shown, and a short discussion about the transient behavior of the charge motion in this engine set-up is given. The third part describes the analysis of the influence of the fuel injection on the charge motion at different engine speeds from 1000 to 3000 r/min and variations of the intake pressure from 1 to 2 bar. Finally, the impact on different flow field properties at possible ignition timings is discussed. Changes in mean flow field quantities as well as in aerodynamic fluctuations are found as a consequence of fuel injection.


Author(s):  
Mohammad Fatouraie ◽  
Margaret S. Wooldridge ◽  
Benjamin R. Petersen ◽  
Steven T. Wooldridge

The effects of ethanol on spray development and wall impingement of a direct injection spark ignition (DISI) engine was investigated using high-speed imaging of the fuel spray in an optically-accessible engine. Neat anhydrous ethanol (E100), reference grade gasoline (E0) and a 50% blend (by volume) of gasoline and ethanol (E50) were used in the study. The experiments were conducted using continuous firing conditions for an intake manifold absolute pressure of 57 kPA, and engine speed of 1500 RPM. Retarded fuel injection timing was used (with start of injection at 250 °bTDC) to isolate the effects of cylinder wall impingement, and lean fuel-to-air ratios (ϕ=0.8–0.9) were used to minimize sooting and coating of the transparent cylinder liner. The effects of three engine coolant temperatures (25, 60 and 90 °C) and two fuel rail pressures (100 and 150 bar) on the features of the spray and the spray interaction with the wall were studied for the different fuels. Quantitative metrics were defined to analyze the spatial features of the spray related to wall impingement. Gasoline (E0) sprays exhibited higher sensitivity to coolant temperature compared to ethanol (E100) in terms of the shape of the spray and wall impingement. Higher fuel injection pressure increased the spray tip penetration rate and fuel impingement with the wall for E0 and E100, despite creating wider plume angles of the fuel sprays.


2011 ◽  
Vol 25 (12) ◽  
pp. 5549-5561 ◽  
Author(s):  
Matthias Thewes ◽  
Martin Muether ◽  
Stefan Pischinger ◽  
Matthias Budde ◽  
André Brunn ◽  
...  

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