Improving the Numerical Accuracy of Spray Simulations University of Massachusetts-Amherst

Format:

Book

Conference/Event

Author/Creator:

Schmidt, David P., author.

Conference Name:

SAE 2002 World Congress & Exhibition (2002-03-04 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2002

Summary:

Lagrangian particle tracking has proven very useful for IC engine spray simulations. However, traditional techniques have been very susceptible to grid dependency. As a consequence, predicted engine performance can depend on the computational mesh. The two main causes of this problem are the collision algorithm and the inter-phase coupling. Using the No Time Counter droplet collision algorithm with an embedded collision mesh practically eliminates grid dependency as a consequence of the collision algorithm. The remaining grid dependency is due to numerical error of the gas phase near the injector and problems with coupling the gas phase and liquid phase. Calculations were made using a novel interpolation scheme that takes advantage of the polar symmetry in the spray. The scheme transforms the velocities into their polar components before doing interpolation. The results show a dramatic decrease in grid dependency. With these changes, the uncertainty in average drop size was reduced from 40 microns to 4 microns in a three dimensional bomb calculation. Spray penetration consistency was also improved. Results from an engine simulation show a more moderate benefit from the improvements

Notes:

Vendor supplied data

Publisher Number:

2002-01-1113

Access Restriction:

Restricted for use by site license