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Active Control of Cylinder Charge Motion Using Vortex Generating Jets (VGJs) on Generic Intake Port Geometries
Journal Article
03-11-04-0032
ISSN: 1946-3936, e-ISSN: 1946-3944
Sector:
Topic:
Citation:
Sun, S., Eilts, P., Scholz, P., and Haubold, S., "Active Control of Cylinder Charge Motion Using Vortex Generating Jets (VGJs) on Generic Intake Port Geometries," SAE Int. J. Engines 11(4):475-490, 2018, https://doi.org/10.4271/03-11-04-0032.
Language:
English
Abstract:
Swirl is known to have impact on the combustion process and the engine emission
performance. Generally the swirl flows are generated on engines by e.g. helical
or tangential intake ports. However, such features of intake ports constrict the
airflow, resulting in raising pumping losses and thus higher fuel consumption.
This article introduces a further possibility to generate and regulate the swirl
flow by injecting air directly into the intake ports using Vortex Generating
Jets (VGJs). The effect of air injection was studied by means of experimental
investigations regarding swirl generation and flow rate improvement. The
optimization of VGJ diameters, positions as well as injection airflow rate was
carried out with respect to energy efficiency of swirl generation. A new
methodology for constructing generic intake ports was developed which specifies
realistic intake port geometries with about 20 parameters and enables the
derivation of comparable intake ports of desirable characteristics. By using
this methodology, one set of generic intake ports was built which has a
significant helical form and shows accordingly strong swirl ratios (referred to
as “ref-ports”). Based on its geometries, a second set of intake ports (referred
to as “jet-ports”) was derived that has a less helical form and shows therefore
reduced swirl ratios but larger flow rates. The swirl intensity of the jet-ports
was then enhanced by VGJs. The experiments show that the VGJs on the jet-ports
can raise the swirl ratio to the level of the ref-ports, while the flow rates
can be further improved by air injection in a certain airflow range. The
influence of air injection on engine operations has been analyzed by means of a
1-D engine simulation. The results show the possibility as well as the potential
of VGJs in view of improving fuel consumption and introducing more variability
for charge motion control.