An assessment of CFD applied to steady flow in a planar diffuser upstream of an automotive catalyst

S. Porter, A.K. Mat Yamin, Svetlana Aleksandrova, Stephen F. Benjamin, Carol A. Roberts, Jonathan Saul

Research output: Contribution to journalArticle

3 Citations (Scopus)
47 Downloads (Pure)

Abstract

Flow maldistribution across automotive exhaust catalysts significantly affects their conversion efficiency. Flow behaviour can be predicted using computational fluid dynamics (CFD). This study investigates the application of CFD to modelling flow in a 2D system consisting of a catalyst monolith downstream of a wide-angled planar diffuser presented with steady flow. Two distinct approaches, porous medium and individual channels, are used to model monoliths of length 27 mm and 100 mm. Flow predictions are compared to particle image velocimetry (PIV) measurements made in the diffuser and hot wire anemometry (HWA) data taken downstream of the monolith. Both simulations compare favourably with PIV measurements, although the models underestimate the degree of mixing in the shear layer at the periphery of the emerging jet. Tangential velocities are predicted well in the central jet region but are overestimated elsewhere, especially at the closest measured distance, 2.5 mm from the monolith. The individual channels model is found to provide a more consistently accurate velocity profile downstream of the monolith. Maximum velocities, on the centre line and at the secondary peak near to the wall, are reasonably well matched for the cases where the flow is more maldistributed. Under these conditions, a porous medium model remains attractive because of low computational demand. Publisher statement: Copyright © 2014 SAE International. This paper is posted on this site with permission from SAE International and is for viewing only. It may not be stored on any additional repositories or retrieval systems. Further use or distribution is not permitted without permission from SAE.
Original languageEnglish
Pages (from-to)1697-1704
JournalSAE International Journal of Engines
Volume7
Issue number4
DOIs
Publication statusPublished - 2014

Fingerprint

Diffusers (fluid)
Steady flow
Computational fluid dynamics
Catalysts
Velocity measurement
Porous materials
Conversion efficiency
Wire

Bibliographical note

Paper presented at the SAE 2014 International Powertrain, Fuels & Lubricants Meeting October 20-23, 2014, Birmingham UK. SAE Technical paper no. 2014-01-2588.
Copyright © 2014 SAE International. This paper is posted on this site with permission from SAE International and is for viewing only. It may not be stored on any additional repositories or retrieval systems. Further use or distribution is not permitted without permission from SAE.

Keywords

  • CFD
  • automotive catalyst
  • steady flow
  • individual channel
  • planar diffuser

Cite this

An assessment of CFD applied to steady flow in a planar diffuser upstream of an automotive catalyst. / Porter, S.; Mat Yamin, A.K.; Aleksandrova, Svetlana; Benjamin, Stephen F.; Roberts, Carol A.; Saul, Jonathan.

In: SAE International Journal of Engines, Vol. 7, No. 4, 2014, p. 1697-1704.

Research output: Contribution to journalArticle

Porter, S. ; Mat Yamin, A.K. ; Aleksandrova, Svetlana ; Benjamin, Stephen F. ; Roberts, Carol A. ; Saul, Jonathan. / An assessment of CFD applied to steady flow in a planar diffuser upstream of an automotive catalyst. In: SAE International Journal of Engines. 2014 ; Vol. 7, No. 4. pp. 1697-1704.
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