Alternative method to evaluate discharge coefficients. Part 2: case study

R.I. Gault, David Thornhill, Robert Fleck

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The purpose of this article is to apply an alternative method whereby discharge coefficients can be estimated for the flow through a poppet valve at various lifts. Presented is the development of an operational quasi-steady flow rig. An engine cylinder head poppet valve was used as the case study. The requirement to directly measure mass flowrates using a standard conventional steady flow apparatus has been eliminated. Transient mass flowrates, pressures and temperatures of air during an inflow test for a poppet valve at various lifts were measured. Mass flowrates were also calculated from measured cylinder gas pressures and corrected for heat transfer. Using both methods to determine the mass flowrates, isentropic discharge coefficients were calculated and shown to compare within +/- 4.0 per cent of steady flow data. A computational fluid dynamics (CFD) validation of the quasi-steady flow rig is also presented.
Original languageEnglish
Pages (from-to)627-636
Number of pages10
JournalProceedings of the institute of mechanical engineers Part C: Journal of Mechanical engineering science
Issue number3
Publication statusPublished - Mar 2009

ASJC Scopus subject areas

  • Mechanical Engineering


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