A Feasible CFD Methodology for Gasoline Intake Flow Optimization in a HEV Application - Part 1: Development and Validation Caterpillar Incorporated

Format:

Conference/Event

Author/Creator:

Qi, Qi, author.

Contributor:

Liu, Hao

Midkiff, Kenneth

Puzinauskas, P. (Paulius)

Conference Name:

SAE 2010 Powertrains Fuels & Lubricants Meeting (2010-10-25 : San Diego, California, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2010

Summary:

Hybrid vehicle engines modified for high exhaust gasrecirculation (EGR) are a good choice for high efficiency and lowNOx emissions. Such operation can result in an HEV when a downsizedengine is used at high load for a large fraction of its run time torecharge the battery or provide acceleration assist. However, highEGR will dilute the engine charge and may cause serious performanceproblems such as incomplete combustion, torque fluctuation, andengine misfire. An efficient way to overcome these drawbacks is tointensify tumble leading to increased turbulent intensity at thetime of ignition. The enhancement of turbulent intensity willincrease flame velocity and improve combustion quality, thereforeincreasing engine tolerance to higher EGR.It is accepted that the detailed experimental characterizationof flow field near top dead center (TDC) in an engine environmentis no longer practical and cost effective. Instead, CFD is moreconvenient, more economical, and more versatile to study thein-cylinder flow physics if its accuracy is validated withexperimental results. To achieve the goal of increasing toleranceto EGR, this work reports investigations of intake port designsimulation.Part 1 of this two-part paper presents a CFD simulationmethodology. It includes a preliminary study of software selectionand a systematic validation study to verify the accuracy of the CFDtool. The validations were performed through the comparison withPIV experimental tests. An assessment of the standard k-ε (SKE),renormalization group k-ε (RNG), and Reynolds stress model (RSM)turbulence models were performed for a series of intake valve liftand intake pressure combination. The results indicate that SKE isthe best suited over RNG and RSM models as it is most accurate, atleast for the current test conditions. The investigation of gridindependence and parameter sensitivity study is also presented. Thedeveloped CFD methodology is applied, in Part 2, for a new intakeport design with a transient study of real engine operationconditions to determine the effectiveness of the optimizedshape

Notes:

Vendor supplied data

Publisher Number:

2010-01-2239

Access Restriction:

Restricted for use by site license