Development of a 0D Model Starting from Different RANS CFD Tumble Flow Fields in Order to Predict the Turbulence Evolution at Ignition Timing University of Bologna

Format:

Conference/Event

Author/Creator:

Falfari, Falfari, author.

Contributor:

Bianchi, Gian Marco

Brusiani, Federico

Catellani, Cristian

Cazzoli, Giulio

Forte, Claudio

Conference Name:

SAE/JSAE 2014 Small Engine Technology Conference & Exhibition (2014-11-18 : Pisa, Italy)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2014

Summary:

AbstractFaster combustion and lower cycle-to-cycle variability are mandatory tasks for naturally aspirated engines to reduce emission levels and to increase engine efficiency. The promotion of a stable and coherent tumble structure is considered as one of the best way to promote the in-cylinder turbulence and therefore the combustion velocity. During the compression stroke the tumble vortex is deformed, accelerated and its breakdown in smaller eddies leads to the turbulence enhancement process.The prediction of the final level of turbulence for a particular engine operating point is crucial during the engine design process because it represents a practical comparative means for different engine solutions. The tumble ratio parameter value represents a first step toward the evaluation of the turbulence level at ignition time, but it has an intrinsic limit. The tumble ratio parameter represents the value of the angular velocity of a single macro vortex, while the flow-field is often characterized by multiple vortexes, sometimes some rotating and some counter-rotating.The idea at the basis of the paper is:Finally the flow field structure could be used in the 0D model on varying the engine speeds as a means of improvement of the model prediction capability

Notes:

Vendor supplied data

Publisher Number:

2014-32-0048

Access Restriction:

Restricted for use by site license