Minor Losses

Minor Loss — Sudden Contraction

Head loss when a pipe contracts abruptly from D1 to D2. The downstream velocity V2 is used.

Formula
hL = Kc · V2² / (2g)
Resultlive
Area ratio, A2/A1
0.250
Loss coefficient, Kc
0.385
Velocity head, V2²/2g
0.20387m
Head loss, hL
0.078491m
Reference: Weisbach's coefficient table for sudden contraction (table interpolated linearly).