Accurate Measurement of Inner Contour and Discharge Coefficient of Sonic Venturi Nozzles

1993 Transactions of the Society of Instrument and Control Engineers  
Discharge coefficients and inner contour of 24 sonic Venturi nozzles, which had various shapes at their throats, were measured by a constant volume tank system developed as the primary standard in Japan and a coordinate measuring machine, respectively. The nozzles, diameters of which ranged from 6.7 to 18.9mm, had been made by a super-precise machine tool and the deviation of the inner contour from the throat. The measured discharge coefficients of the nozzles, which had the toroidal throats
more » ... plying with the ISO, coincided with the ISO within the specified uncertainty at the Reynolds number from 0.6 to lower projections than the boundary layer thickness at their throats and depressions of similar dimension of the thickness right after the projections, were larger by 0.2-0.3% and had smaller dependency on the Reynolds number than the ordinary ISO nozzles.
doi:10.9746/sicetr1965.29.1036 fatcat:565kri5y4ffh7bzxhavpigupbm