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Interaction of Airflow and Injected Fuel Spray Inside the Intake Port of a Six Cylinder Four Valve SI Engine
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Abstract
Measurements of crank angle resolved air velocity and fuel droplet velocity inside the intake port of a six cylinder four valve production engine were performed using two component Laser Doppler Velocimetry (LDV). Prior to the engine measurements the fuel injector was characterized by determining time resolved droplet sizes and velocities with Phase Doppler Velocimetry (PDV) at an injector test rig with complete optical access.
PDV results indicate that during spray penetration into quiescent air at atmospheric pressure (test rig conditions) large droplets move at the tip of the spray while small droplets due to their low force of inertia are slowed down by aerodynamic pressure and pile up at the end of the spray. Mean values of the droplet diameter rise with the distance from the injector because the smallest droplets do not reach the downstream measurement locations.
Engine measurements show the behaviour of the injected fuel spray in a highly transient airflow inside the intake port. Under part load conditions the spray is affected by velocity waves running through intake port and manifold. Fuel droplets remaining in the air are accelerated and slowed down through the wave motion which is induced by the pressure differential between cylinder and intake port at intake valve opening. Finally, an estimation of the maximum relative velocity between droplets and air shows that secondary atomization of droplets due to aerodynamic pressure inside the intake port can support mixture formation at high engine speed, high engine load and open valve injection into maximum air velocity.
Authors
Citation
Schūnemann, E., Münch, K., and Leipertz, A., "Interaction of Airflow and Injected Fuel Spray Inside the Intake Port of a Six Cylinder Four Valve SI Engine," SAE Technical Paper 972984, 1997, https://doi.org/10.4271/972984.Also In
References
- Münch K.-U. Leipertz A. “Mixture Formation in Gasoline and Diesel Engines Investigated by Advanced Measurement Techniques” Proc. 26. FISITA Congress Prague 1996
- Wittig S. Himmelsbach J. Hallmann M. Samenfink W. Elsāβer A. 55 160 166 1994
- Münch K.-U. Wensing M. Schünemann E. Leipertz A. “Characterization of Port Fuel Injection Sprays” Paper in Preparation 1997
- Johnen T. Haug M. “Spray Formation Observation and Fuel Film Development Measurements in the Intake of a Spark Ignition Engine” SAE Paper 950511 1995
- Münch K.-U. Krämer H. Leipertz A. “Investigation of Fuel Evaporation Inside the Intake of a SI Engine Using Laser-Induced Exciplex-Fluorescence With a New Seed” SAE Paper 961930 1996
- Zhao F.-Q. Lai M.-C. Harrington D.L. “The Spray Characteristics of Automotive Port Fuel Injection-A Critical Review” SAE Paper 950506 1995
- Vannobel F. Dementhon J. B. Robart D. “Phase Doppler Anemometry Measurements on a Gasoline Spray inside the Inlet Port and Downstream of the Induction Valve; Steady Flow Conditions” Laser Techniques and Applications in Fluid Mechanics, Proc. of the 6 th International Symposium Heitor M. V. Maeda M. Whitelaw J. H. Springer-Verlag 1992
- Brenn G. Domnick J. Dorfner V: Durst F. “Unsteady Gasoline Injection Experiments: Comparison of Measurements in Quiescent Air and in a Model Intake Port” SAE Paper 950512 1995
- Lai M.-C. Zhao F.-Q. Amer A. A. Chue T.-H. “An Experimental and Analytical Investigation of the Spray Structure from Automotive Port Injectors” SAE Paper 941873
- Nemecek L. Wagner R. M. Drallmeier J. A. “Fuel Droplet Entrainment Studies for Minimization of Cold Start Wetting” SAE Paper 950308 1995
- Lide D.R. “CRC-Handbook of Chemistry and Physics” CRC Press Boca Raton 1994
- Hjelmfelt A. T. Mockros L. F. “Motion of Discret Particles in a Turbulent Fluid” App. Sci. Res 16 149 161 1966
- Pilch M. Erdman C. A. “Use of Breakup Time Data and Velocity History Data to Predict the Maximum Size of Stable Fragments for Acceleration-Induced Breakup of a Liquid Drop” International Journal of Multiphase Flow 13 1987 6 741 757 1987