PRESSURE DROP THROUGH BEVELLED MULTIHOLE ORIFICES IN SERIES. (PWR Blanket Design)

Abstract

The continuation of a study of pressure drop across various combinations of staggered multihole orifice plates in series is described. Plates used in this test contained bevelled leading edge holes and were of the general design proposed for fiow control in the PWR blanket region. Variables examined in this test were orifice diameters of 0.300, and 0.625 in., one to six plates in series, and flow rates corresponding to orifice Reynold's numbers ranging from 15,000 to 140,000. The orifice plates and experimental methods employed in this test were similar to those described in the preceding orifice plate report. WAPDTH-241 (41 holes on a 0.486 in. square pitch located in a 4.195 in. diameter pipe), with the exception that the present plates had a 3O deg bevel around the leading edge of each hole sufficient in depth to make the bevelled diameter 1/16 in. larger than the hole diameter. Results are given as pressure loss coefficients (number of orifice velocity heads), and were found to be about 50% less than comparable values for squarc edge orifices. In general, Reynolds's number had no effect upon the loss coefficients. The loss coefficients are estimated to be accurate within plus or minus 10% overmore » the range investigated. (auth)« less