Browse Publications Technical Papers 2005-01-3686

The Directstart: Investigation of Mixture Formation by Means of Optical Measurements and 3D-CFD-Simulation 2005-01-3686

This paper focuses onto mixture formation issues of the Directstart of a gasoline direct injection engine.
Regarding the starterless Directstart, i.e. an engine start through targeted injection and ignition timing without the help of an electrical starter, engine tests show that there exists a large room for improvements by attending the mixture formation of the first combustion.
The conditions for the first combustion are very unusual: ambient pressure, nearly the same fuel, engine and charge temperature, no piston movement and only spray induced turbulence. Furthermore, engine tests show that the mixture formation changes with the engine temperature.
This paper analyzes the mixture formation of the first combustion for different engine conditions by means of engine measurements and both optical measurements in a spray chamber and simulations performed by the fast response 3D-CFD-Tool QuickSim of IVK/FKFS. In particular, the differences between single and multiple injections are evaluated.


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


Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.