This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
The Influence of Hydro Grinding at VCO Nozzles on the Mixture Preparation in a DI Diesel Engine
Annotation ability available
Sector:
Language:
English
Abstract
The hydro grinding process can be used for valve covered orifice (VCO) nozzle production. A comprehensive numerical and experimental investigation was performed to determine the influence of hydro grinding (HG) at VCO nozzles on the mixture preparation in pressure charged high speed direct injection diesel engines.
Samples of five hole VCO nozzles with defined grades of HG and different sprayhole diameters were selected to ensure a constant mass flow at a fixed feeding pressure for comparable engine tests. The simulation of the internal flow shows a more symmetrical velocity profile indicating less shear flow and lower turbulence intensities at the orifice with increased HG grade. From these results an enhanced atomization at further penetration depth and reduced atomization close to the nozzle could be expected. This was confirmed by measuring the spray momentum distribution and spray tip speed by mechanical and optical probes in high pressure vessels. The experiments at an optical access high s peed direct injection (HSDI) engine confirmed these results under dynamic engine pressure and temperature conditions and additionally exhibited changes in wall impingement. Experiments at a charged HSDI single cylinder engine showed a significant improvement in smoke emissions with increasing HG grade at a full load high speed operation point.
From our results we can conclude that the modified spray features due to the HG process meet the demands of pressure charged HSDI engines for mixture preparation.
Recommended Content
| Technical Paper | Influence of Injection Nozzle Improvement on DI Diesel Engine |
| Technical Paper | Quantification of the Internal Surface Roughness of Cast Iron Exhaust Manifolds |
| Technical Paper | Correlating the Diesel Spray Behavior to Nozzle Design |
Authors
Citation
Kampmann, S., Dittus, B., Mattes, P., and Kirner, M., "The Influence of Hydro Grinding at VCO Nozzles on the Mixture Preparation in a DI Diesel Engine," SAE Technical Paper 960867, 1996, https://doi.org/10.4271/960867.Also In
References
- Yoshikawa S. Furusawa R. Arai M. Hiroyasu H. “Optimizing Spray Behaviour to Improve Engine Performance and to Reduce Exhaust Emissions in a Small D.J. Diesel Engine” SAE paper 890463 1989
- Hiroyasu H. Arai M. “Structures of Fuel Sprays in Diesel Engines” SAE paper 900475 1990
- Pierpont D.A. Reitz R.D. “Effects of Injection Pressure and Nozzle Geometr on D.I. Diesel Emissions and Performance” SAE paper 950604 1995
- Ohrn R. Senser D.W. Lefebvre A. H. “Geometrical Effects on Discharge Coefficients for Plain-Orifice Atomizers” Atomization and Sprays 1 137 153 1991
- Knox-Kelecy A.L. Farrell P.V. “Spectral Characteristics of Turbulent Flow in a Scale Model of a Diesel Fuel Inector Nozzle” SAE paper 930924 1993
- Heine B. “Flow Calculations in Injection Systems” Proceedings of the 1st Int. FIRE user meeting Graz, Austria 1993
- Komaroff I. Melcher K. 1971