Effect of Misalignment of Penstocks on Head Loss

Abstract

A penstock is a conduit which is normally used to convey water from a reservoir to hydraulic turbines. It is made by joining a number of pieces of pipe whose proper alignments are essential to minimize the flow disturbances and hydraulic losses. This paper experimentally investigates the effect of misalignment of two pipes of the same diameter on hydraulic losses at five different Reynolds numbers ranging from 5.34 × 105 to 6.22 × 105. The diametric misalignment between the two pieces of mild steel penstock of inner diameter 342 mm is varied from 2 to 10 mm in steps of 2 mm. There is a loss of pressure head at the location of mismatch of the diameters, which increases with increase in misalignment and Reynolds number.