Studies on Fluid Flow in Three-Dimensional Bend Conduits

Abstract

This paper gives the results of the experimental study of loss and secondary circulation due to various combinations of commercial elbows, and discussed the relationship between the loss and the circulation. Three general combinations are ; One where the two elbows produce a complete reversal in the direction of flow, termed the"U"bend ; and two where the two elbows produce an offset but no change in direction, termed the"S"bend ; and three where the two elbows produce both an offset and a 90 degree change in the direction of flow, termed the"twisted S"bend. The last combination gives rise to a strong single spiral motion in the straight pipe of curved pipes downstream and shows the maximum bend loss.