HYDRAULIC MODEL OF TRICKLE-IRRIGATION LATERALS - IWRA

5
-2 5
7
for 2000 < Re ≤ 10 , K
0
= 9,2794x10
for 10 < Re ≤ 10 . The coefficient of Boussinesq
for laminar flow is α = 1,33 and for turbulent flow is α = 1, 10 . The coefficient of
proportionality between the longitudinal projection of discharged velocity and the
averaged flow velocity throughout the cross-section is δ = 0, 1.
The first boundary condition of the model for the given example is:
x = 0 Q = Q0
= Nq = 407,75l/h h = h0
= 1bar
The second boundary condition is calculated by the program.
The results calculated are drawn in diagrams: pressure head h = f (x) along the
lateral length is shown in Fig. 5; dripline flow rate Q = f ( x)
in Fig. 6; emitter
discharge q in Fig.7 ; Re = f ( x)
in Fig. 8; n = f (Re, x)
in Fig. 9; m = f (Re, x) in
Fig. 10; K = (Re, x) in Fig. 11; coefficient of Boussinesq α in Fig. 12, respectively.
0
f
8. Results from the program
Dripline Flow Rate Q(l/h)
400
350
300
250
200
150
100
50
0
0 10 20 30 40 50 60 70
Lateral Length l(m)
Fig.6. Distribution of pressure head
h along the lateral length l
Pressure Head h(m)
10
9.9
9.8
9.7
9.6
9.5
9.4
9.3
9.2
9.1
9
0 10 20 30 40 50 60 70
Lateral Length l(m)
Fig.7. Distribution of drip line flow rate
along the lateral length l
1.76
14000
Emitter Discharge q(l/h)
1.74
1.72
1.7
1.68
Reynolds Number Re
12000
10000
8000
6000
4000
2000
1.66
0 10 20 30 40 50 60 70
Lateral Length l(m)
0
0 10 20 30 40 50 60 70
Lateral Length l(m)
Fig.8. Distribution of emitter discharge
along the lateral length l
Fig.9. Distribution of Reynolds
number along the lateral length
8