On the definition of a small orifice
Abstract
An attempt is made to draw a line of demarcation between small orifices and large orifices. It is proposed that an orifice can be considered 'small' if the discharge through it calculated on the smallorifice assumption differs from the exact discharge by less than half of one per cent. Using this criterion, it is shown that a circular or elliptic orifice can be deemed 'small' as long as the ratio of the depth of the orifice to the head causing the flow (measured from the center of the orifice to the liquid surface) is less than 0.8; a rectangular orifice can be deemed 'small' if the ratio is less than 0.7. A correction factor is suggested for the coefficient of discharge to account for the deviation from the exact discharge.
 Publication:

Acta Technica
 Pub Date:
 1975
 Bibcode:
 1975AcTec..80..419M
 Keywords:

 Discharge Coefficient;
 Liquid Flow;
 Nozzle Design;
 Nozzle Geometry;
 Orifice Flow;
 Circles (Geometry);
 Cross Sections;
 Ellipses;
 Rectangles;
 Fluid Mechanics and Heat Transfer