HEAD-LOSS OF A T-JUNCTION Objectives: Determination of the head-losses of a T-junction under various operating conditions

Abstract At a projected pump-storage power plant different operation conditions are necessary due to regulation processes. Thereby inflow and outflow conditions in the T-junctions, which are located between the pumps and turbines, are changed rapidly. To quantify the hydraulic properties and head losses of the T-junction physical model tests were conducted

res

pu

tu

C1

res

pu

tu

C2

res

pu

tu

C3

res

pu

tu

C4

res

pu

tu

C5

Operating conditions

Piezometrictubes

Computer

IDMPressure gauges

Difference pressuresensor

Piezometrictubes

Computer

IDMPressure gauges

Difference pressuresensor

Experimental set-up

The head-loss coefficient of the T-junction is determined by:

g2vjtoifromfrictionpipejbranchinpressuretotalibranchinpressuretotalK 2

mij

−−=

loss-coefficient case 5 (based on v pu)

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

-2.00 -1.80 -1.60 -1.40 -1.20 -1.00 -0.80 -0.60 -0.40 -0.20 0.00

q=Q(res)/Q(pu)

loss

-coe

ffic

ient

K

K pu-res K pu-res case 4K tu-res K tu-res case 4K pu-tu K pu-tu case 4

loss-coefficient case 3 (based on v pu)

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

q=Q(res)/Q(pu)

loss

-coe

ffici

ent K

K pu-res case 4 K pu-res K pu-res case 2K tu-res case 4 K tu-res K tu-res case 2K pu-tu case 4 K pu-tu K pu-tu case 2

Project team: B. Huber, K. Fuchs

References: 1. Miller, D.S. (1978). Internal Flow Systems, BHRA Fluid Engineering, Vol. 5