This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Influence of Elevated Injector Temperature on the Spray Characteristics of GDI Sprays
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 2, 2019 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
When fuel at elevated temperatures is injected into an ambient environment at a pressure lower than the saturation pressure of the fuel, the fuel vaporizes in the nozzle and/or immediately upon exiting the nozzle; that is, it undergoes flash boiling. It is characterized by a two-phase flow regime co-located with primary breakup, which significantly affects the spray characteristics. Under flash boiling conditions, the near nozzle spray angle increases, which can lead to shorter penetration because of increased entrainment. In a multi-hole injector this can cause other impacts downstream resulting from the increased plume to plume interactions.
To study the effect of injector temperature and injection pressure with real fuels, an experimental investigation of the spray characteristics of a summer grade gasoline fuel with 10% ethanol (E10) was conducted in an optically accessible constant volume spray vessel. A gasoline direct-injection injector with six holes typical of a side-injection engine was studied. Optical diagnostics included high-speed photography with alternate frame imaging from Mie-Scattering and Shadowgraph techniques. Ambient conditions representing Early Injection (45°C, 1 bar) and Late Injection (180°C, 4bar) conditions representative of gasoline direct injection events were studied at injector temperatures from 75 to 250°C and at injection pressures of 100, 150, 200 and 250 bar.
Results showed that for early injection condition, increased fuel temperature leads to two primary effects due to flash boiling: (i) an appreciable increase in spray angle near the nozzle exit followed by (ii) a decrease downstream of the nozzle due to the interaction of the plumes and collapsing sprays. For the early injection condition, spray penetration was observed to be minimum at 100°C followed by an increase in penetration at higher temperatures due to the collapsing sprays. For the late injection condition, the spray angle at the exit and downstream of the nozzle decreased with temperature. Besides, increased injection pressures lead to increased spray penetration due to higher injection momentum of the sprays outperforming the plume to plume interactions.
CitationMiganakallu Narasimhamurthy, N., Atkinson, W., Yang, Z., and Naber, J., "Influence of Elevated Injector Temperature on the Spray Characteristics of GDI Sprays," SAE Technical Paper 2019-01-0268, 2019, https://doi.org/10.4271/2019-01-0268.
Data Sets - Support Documents
|[Unnamed Dataset 1]|
|[Unnamed Dataset 2]|
|[Unnamed Dataset 3]|
- Schulz, F. and Beyrau, F., “The Influence of Flash-Boiling on Spray-Targeting and Fuel Film Formation,” Fuel 208:587-594, 2017, doi:10.1016/j.fuel.2017.07.047.
- Wu, S., Xu, M., Hung, D.L.S., Li, T. et al., “Near-Nozzle Spray and Spray Collapse Characteristics of Spark-Ignition Direct-Injection Fuel Injectors under Sub-Cooled and Superheated Conditions,” Fuel 183:322-334, 2016, doi:10.1016/j.fuel.2016.06.080.
- Xu, M., Zhang, Y., Zeng, W., Zhang, G. et al., “Flash Boiling: Easy and Better Way to Generate Ideal Sprays than the High Injection Pressure,” SAE Int. J. Fuels Lubr 6(1):137-148, 2013, doi:10.4271/2013-01-1614.
- Chan, Q.N., Bao, Y., and Kook, S., “Effects of Injection Pressure on the Structural Transformation of Flash-Boiling Sprays of Gasoline and Ethanol in a Spark-Ignition Direct-Injection (SIDI) Engine,” Fuel 130:228-240, 2014, doi:10.1016/j.fuel.2014.04.015.
- Araneo, L., Coghe, A., Brunello, G., and Dondé, R., “Effects of Fuel Temperature and Ambient Pressure on a GDI Swirled Injector Spray,” SAE Technical Paper 2000-01-1901, 2000, doi:10.4271/2000-01-1901.
- Huang, Y., Huang, S., Huang, R., and Hong, G., “Spray and Evaporation Characteristics of Ethanol and Gasoline Direct Injection in Non-Evaporating, Transition and Flash-Boiling Conditions,” Energy Conversion and Management. 108:68-77, 2016, doi:10.1016/j.enconman.2015.10.081.
- Daly, S., Cenker, E., Pickett, L., and Skeen, S., “The Effects of Injector Temperature on Spray Characteristics in Heavy-Duty Diesel Sprays,” SAE Technical Paper 2018-01-0284, 2018, doi:10.4271/2018-01-0284.
- Hwang, J., Park, Y., Bae, C., Lee, J. et al., “Fuel Temperature Influence on Spray and Combustion Characteristics in a Constant Volume Combustion Chamber (CVCC) under Simulated Engine Operating Conditions,” Fuel 160:424-433, 2015, doi:10.1016/j.fuel.2015.08.004.
- Zeng, W., Xu, M., Zhang, G., Zhang, Y. et al., “Atomization and Vaporization for Flash-Boiling Multi-Hole Sprays with Alcohol Fuels,” Fuel 95:287-297, 2012, doi:10.1016/j.fuel.2011.08.048.
- Tang, M., Pei, Y., Zhang, Y., Tzanetakis, T. et al., “Development of a Transient Spray Cone Angle Correlation for CFD Simulations at Diesel Engine Conditions,” SAE Technical Paper 2018-01-0304, 2018, doi:10.4271/2018-01-0304.
- Parrish, S., “Evaluation of Liquid and Vapor Penetration of Sprays from a Multi-Hole Gasoline Fuel Injector Operating under Engine-Like Conditions,” SAE Int. J. Engines 7(2):1017-1033, 2014, doi:10.4271/2014-01-1409.
- Naber, J. and Siebers, D., “Effects of Gas Density and Vaporization on Penetration and Dispersion of Diesel Sprays,” SAE Technical Paper 960034, 1996, doi:/10.4271/960034.
- Parrish, S., Zhang, G., and Zink, R., “Liquid and Vapor Envelopes of Sprays from a Multi-Hole Fuel Injector Operating under Closely-Spaced Double-Injection Conditions,” SAE Int. J. Engines 5(2):400-414, 2012, doi:10.4271/2012-01-0462.
- Schmitz, I., Ipp, W., and Leipertz, A., “Flash Boiling Effects on the Development of Gasoline Direct-Injection Engine Sprays,” SAE Technical Paper 2002-01-2661, 2002, doi:10.4271/2002-01-2661.
- Hung, D., Harrington, D., Gandhi, A., Markle, L. et al., “Gasoline Fuel Injector Spray Measurement and Characterization - A New SAE J2715 Recommended Practice,” SAE Int. J. Fuels Lubr. 1(1):534-548, 2009, doi:10.4271/2008-01-1068.
- Nesbitt, J.E., “Diesel Spray Mixing Limited Vaporization with Non-Ideal and Multi-Component Fuel Thermophysical Property Effects,” Ph.D. thesis, Mechanical Engineering Department, Michigan Technological University, 2011.