Large Eddy Simulation of a Transient Air Jet with Emphasis on Entrainment during Deceleration Sandia National Laboratories

Format:

Conference/Event

Author/Creator:

Hu, Hu, author.

Contributor:

Musculus, Mark

Oefelein, Joseph

Conference Name:

SAE 2010 World Congress & Exhibition (2010-04-13 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2010

Summary:

Recent experiments of diesel injection processes have demonstrated that mixing accelerates after the end of injection (EOI). This finding has significant implications for low-temperature combustion (LTC) diesel engines. Previous simulations using a one-dimensional model of a single-pulsed air jet, which is analogous in many aspects to diesel jets, suggest that the rapid mixing after EOI in diesel jets is due to a temporary increase in the entrainment rate as the jet decelerates. In the present study, we performed a high-fidelity large eddy simulation (LES) of an unsteady air jet identical to that used for the one-dimensional model. The LES calculation agrees well with available experimental data and provides both spatially and temporally resolved details of the three-dimensional transient mixing field. Results show that entrainment increases during deceleration. We propose that the enhanced entrainment is due to the growth of the interface between the turbulent jet flow field and the non-turbulent ambient field, and that the growth of this interface is a consequence of the enhanced flow instability that is induced by the deceleration of the jet

Notes:

Vendor supplied data

Publisher Number:

2010-01-1133

Access Restriction:

Restricted for use by site license