1995-10-01

Modeling of Fuel Droplets Deposition Rate in Port Injected Spark Ignition Engine 952484

A very accurate control of air fuel ratio in port injected spark ignition engines during transient is required to reach the toughest polluant emissions standards. The prediction of air fuel ratio behavior has been made with models for liquid fuel film, droplets and fuel vapor in the intake manifold of single point injected engines [1], where the droplet deposition rate on the manifold was only a parameter.
This paper describes a model for droplet deposition rate on the port walls and intake valve in port injected engines. The model described here takes into account the transient character of fuel injection in a real port geometry. The droplet diameter distribution is included with seven different droplet sizes, and varies across the spray, with a multicomponent fuel. The backflow of hot burned gas at valve opening is also taken into account by the model.
The depostion rate on the valve and the port walls as a function of space and time has been calculated for several operating conditions. The droplet diameter distribution, the injector angle as well as the injector-valve distance were also varied.
Finally a comparison of the equivalence ratio calculated with a global model including the deposition rate description with the measured equivalence ratio is given for a transient test, showing a really good correlation between calculated and measured air fuel ratios.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Fuel Transport Characteristics of Spark Ignition Engines for Transient Fuel Compensation

950067

View Details

TECHNICAL PAPER

Effects of Combustion Chamber Shape and Spark Location on Exhaust Nitric Oxide and Hydrocarbon Emissions

740529

View Details

TECHNICAL PAPER

Local Air-Fuel Ratio Measurements Using the Spark Plug as an Ionization Sensor

970856

View Details

X