Abstract
The objective of this study is to measure the response of the orifice meter to known upstream flow field disturbances generated by a concentric tube flow conditioner and a vane-type swirl generator. These disturbances are characterized by flan measuring the axial and tangential velocity profiles at the upstream tap with no orifice plate present. Two different flow rates are examined which correspond to Reynolds numbers of 91,100 and 120,000 in a 50.8 mm diameter pipe. Eight orifice plates with [ ] ratios of 0.43, 0.45, 0.484, 0.55, 0.6, 0.65, 0.7 and 0.726 are studied at both flow rates. The response of each orifice meter to the disturbance is measured by determining the axial pressure distribution near the orifice plate, and by determining the discharge coefficient. The axial momentum distribution is quantified by calculating the second order moment of axial momentum (91 2[U]) from the velocity profile data. Swirl is quantified by determining the centripetal acceleration flux of the flow, also from the velocity profile data. Surface fits indicating the variation of discharge coefficient as a function of P ratio and 9i2[U] or swirl number are developed. These are useful in evaluating variations in the discharge coefficient for flows where the inlet velocity profile has been measured.
Hauglie, Jayden Edward (1994). A study of swirl and axial velocity profile effects on orifice flowmeters. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1994 -THESIS -H371.