A Comprehensive Numerical Study of Diesel Fuel Spray Formation with OpenFOAM Chalmers Univ. of Technology

Format:

Conference/Event

Author/Creator:

Kösters, Kösters, author.

Contributor:

Karlsson, Anders

Conference Name:

SAE 2011 World Congress & Exhibition (2011-04-12 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2011

Summary:

The accuracy and robustness of spray models and theirimplementation in current commercial CFD codes vary substantially.However, common features are that the resulting spray penetrationand levels of spray-generated turbulence - two factors thatstrongly influence the rate of heat released during combustion -are to a great extent grid size-dependent.In the work presented here a new kind of spray model has beenimplemented and thoroughly tested, under various ambientconditions, in the open source code OpenFOAM. In addition, sincethe turbulence model applied in simulations is known to stronglyaffect spray penetration rates, results obtained using both thestandard k-ε and RNG k-ε models have been compared.In the new spray model, designated VSB2, the traditionalLagrangian parcel has been replaced by a so-called stochastic blobcontaining droplets with a distribution of sizes, rather than anumber of uniform-sized droplets. These blobs do not interact withthe grid directly, but through bubbles of locally determined size.One advantage of the VSB2 spray model is its less grid sizedependence due to the interaction with the gas phase in the bubblesinstead of the entire grid cell it currently occupies. Anotherbenefit of the model is its robustness, resulting from rigorouscalculation of equilibrium values for momentum and thermodynamic(saturation and temperature) parameters affecting transfer ratesbetween the phases ensuring a bounded solution.Results obtained using the code are compared here withexperimentally acquired data regarding spray penetration undervarious ambient conditions. Qualitative comparisons of the evolvingspray shapes are also presented

Notes:

Vendor supplied data

Publisher Number:

2011-01-0842

Access Restriction:

Restricted for use by site license