Investigation of Influence of Injection Pressure on Gasoline Fuel Spray Characteristics Using Numerical Simulation

Author(s):  
Sandip Wadekar
2016 ◽  
Vol 2016 (0) ◽  
pp. G0700102
Author(s):  
Shun SHIMOTSUMAGARI ◽  
Takeru IWAMOTO ◽  
Masaoki SUGIHARA ◽  
Hideki HASHIMOTO ◽  
Osamu MORIUE

Author(s):  
Sebastian Schuckert ◽  
Oliver Hofmann ◽  
Georg Wachtmeister

Emission performance of combustion engines has gained outstanding importance with both legislators and customers over the past years. Injector aging, such as nozzle wear or coking, results in the deterioration of injection and emission parameters. In this study, the influences of aging effects on injection rate, fuel spray as well as engine performance and emissions were assessed. Nozzles, which had previously been operated in a vehicle engine and were likely to have suffered from aging, showed no aging-induced characteristics during injection rate and spray measurements and were not investigated further. Therefore, nozzles with different nozzle hole diameters were utilized to simulate the different aging effects. Injection rate measurements demonstrated, that for smaller energizing times, a nozzle with smaller nozzle holes can deliver a higher injected mass than a nozzle with bigger nozzle holes. The adaptation of energizing time or injection pressure demonstrated the potential to compensate the change in engine load due to smaller or bigger nozzle holes. For bigger nozzle holes, the adaptation of injection pressure in order to restore the target load returned lower NOx emissions, whereas the adaptation of the energizing time always yielded lower soot emissions compared to the reference nozzle. For small nozzle holes, the optimization of the start of energizing reduced specific NOx emissions without increasing specific soot emissions. The comparison of measured injection rate and fuel spray characteristics to the ones reported in literature confirms the possibility of simulating nozzle wear by increased nozzle holes and coking by smaller nozzle holes. The results of this study are of vital interest to the research of aging effects and add useful knowledge about compensation methods for nozzle aging.


2015 ◽  
Vol 75 ◽  
pp. 919-924 ◽  
Author(s):  
Balaji Mohan ◽  
Wenming Yang ◽  
Wenbin Yu ◽  
Kun Lin Tay ◽  
Siaw Kiang Chou

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Tao Zhang ◽  
Bo Dong ◽  
Xun Zhou ◽  
Linan Guan ◽  
Weizhong Li ◽  
...  

Partial replacement of kerosene by ethanol in a gas turbine is regarded as a good way to improve the spray quality and reduce the fossil energy consumption. The present work is aimed at studying the spray characteristics of kerosene-ethanol blends discharging from a pressure-swirl nozzle. The spray cone angle, discharge coefficient, breakup length, and velocity distribution are obtained by particle image velocimetry, while droplet size is acquired by particle/droplet imaging analysis. Kerosene, E10 (10% ethanol, 90% kerosene), E20 (20% ethanol, 80% kerosene), and E30 (30% ethanol, 70% kerosene) have been considered under the injection pressure of 0.1–1 MPa. The results show that as injection pressure is increased, the discharge coefficient and breakup length decrease, while the spray cone angle, drop size, and spray velocity increase. Meanwhile, the drop size decreases and the spray velocity increases with ethanol concentration when the injection pressure is lower than 0.8 MPa. However, the spray characteristics are not affected obviously by the ethanol concentration when the injection pressure exceeds 0.8 MPa. A relation to breakup length for kerosene-ethanol blends is obtained. The findings demonstrate that the adding of ethanol into kerosene can promote atomization performance.


Author(s):  
Mohammed El Adawy ◽  
Morgan Heikal ◽  
bin Abd. Aziz Abd. Rashid

Abstract RICARDO-VECTIS CFD simulation of the in-cylinder air flow was first validated with those of the experimental results from high-speed particle image velocimetry (PIV) measurements taking cognisant of the mid-cylinder tumble plane. Furthermore, high-speed fuel spray measurements were carried out simultaneously with the intake-generated tumble motion at high valve lift using high-speed time-resolved PIV to chronicle the spatial and time-based development of air/fuel mixture. The effect of injection pressure(32.5 and 35.0 MPa) and pressure variation across the air intake valves(150, 300 and 450 mmH2O) on the interaction process were investigated at valve lift 10 mm where the tumble vortex was fully developed and filled the whole cylinder under steady-state conditions. The PIV results illustrated that the intake generated-tumble motion had a substantial impact on the fuel spray distortion and dispersion inside the cylinder. During the onset of the injection process the tumble motion diverted the spray plume slightly towards the exhaust side before it followed completely the tumble vortex. The fuel spray plume required 7.2 ms, 6.2 ms and 5.9 ms to totally follow the in-cylinder air motion for pressure differences 150, 300 and 450 mmH2O, respectively. Despite, the spray momentum was the same for the same injection pressure, the magnitude of kinetic energy was different for different cases of pressure differences and subsequently the in-cylinder motion strength.


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