CE 3372 WATER SYSTEMS DESIGN LECTURE 9 FITTING

CE 3372 WATER SYSTEMS DESIGN LECTURE 9: FITTING LOSSES

OUTLINE • Fitting Losses • • Darcy-Weisbach Structure Equivalent Length

FITTING (MINOR) LOSSES • Fittings, joints, elbows, inlets, outlets cause additional head loss. • Called “minor” loss not because of magnitude, but because they occur over short distances. • Typical loss model is

FITTING (MINOR) LOSSES • The loss coefficients are tabulated for different kinds of fittings

EXAMPLE – FITTING (MINOR) LOSSES

PIPELINE SYSTEM Length_2 2 Length_1 Exit Elbow =Length_1 + Length_2 1 Inlet Head Loss Model Pump Curve

EXAMPLE • Consider the tworeservoir problem with fitting losses • • • Inlet loss: K=0. 5 Exit loss: K=1. 0 Assume two 45 elbows; K = 0. 4

EXAMPLE • Apply the On-Line Calculator • • • Inlet loss: K=0. 5 Exit loss: K=1. 0 Assume two 45 elbows; K = 0. 4

WATER PROPERTIES • Apply the On-Line Calculator • • • Inlet loss: K=0. 5 Exit loss: K=1. 0 Assume two 45 elbows; K = 0. 4

EXAMPLE • Apply the On-Line Calculator • • • Inlet loss: K=0. 5 Exit loss: K=1. 0 Assume two 45 elbows; K = 0. 4 Set Z 1 and Z 2 so difference is 20 feet

EXAMPLE • Apply the On-Line Calculator • • • Inlet loss: K=0. 5 Exit loss: K=1. 0 Assume two 45 elbows; K = 0. 4

CHECK WORK – REPEAT WITH ) LOSS COEFFICIENTS; COMPARE TO JAIN EQUATION • Obtain nearly the same result, so the case with the loss is is plausible

PIPELINE SYSTEM WITH PUMP Length_2 2 Length_1 Exit Elbow =Length_1 + Length_2 1 Inlet Head Loss Model Pump Curve

NEXT TIME • Pumps and Pump Performance Curves • • Pump Types Pump Curves System Curves Parallel and Series Pumps