Enhancing flow pattern upstream of New Hafeer Pump Station

Peer review under responsibility of National Water Research Center.

Figures & data

Table 1 Reynolds number values in the model.

Drain cross section	Average velocity (m/s) model	Average depth (m) model	Reynolds number model
C.S 1	0.036	0.143	5148 > 2000
C.S 2	0.067	0.134	8978 > 2000
C.S 3	0.047	0.114	5358 > 2000

Fig. 1 HSD physical model general layout.

Fig. 2 Comparison between simulated and observed velocities (C. S. 1).

Fig. 3 Comparison between simulated and observed velocities (C. S. 2).

Fig. 4 Comparison between simulated and observed velocities (C. S. 3).

Fig. 5 Comparison between simulated and observed water levels (HSD right bank).

Fig. 6 Comparison between simulated and observed water levels (HSD left bank).

Table 2 F_critical and corresponding F_value for model calibration.

No.	Returned Fvalue	Fcritical	Pvalue
C.S 1	1.0136	1.8821	0.48 > 0.05
C.S 2	1.2766	2.0478	0.28 > 0.05
C.S 3	1.1942	1.9554	0.33 > 0.05

Table 3 Coefficient of determination for observed and simulated velocities.

No.	A o	A s	Ao − As	(Ao − As)^2	(Ao − A^−o)^2	F2
C.S 1	0.000	0.000	0.000	0.000	0.007	0.980
	−0.100	−0.160	0.060	0.004	0.033
	−0.162	−0.195	0.033	0.001	0.059
	−0.137	−0.150	0.013	0.000	0.048
	−0.075	−0.087	0.012	0.000	0.024
	−0.012	0.027	−0.039	0.002	0.009
	0.070	0.100	−0.030	0.001	0.000
	0.270	0.280	−0.010	0.000	0.036
	0.437	0.412	0.025	0.001	0.127
	0.462	0.480	−0.018	0.000	0.145
	0.400	0.440	−0.040	0.002	0.102
	0.200	0.260	−0.060	0.004	0.014
	−0.075	−0.075	0.000	0.000	0.024
	−0.062	−0.075	0.013	0.000	0.020
	0.000	0.000	0.000	0.000	0.007
Average	0.081		Sum	0.014	0.654
C.S 2	0.000	0.000	0.000	0.000	0.043	0.979
	0.180	0.150	0.030	0.001	0.001
	0.315	0.278	0.037	0.001	0.012
	0.350	0.360	−0.010	0.000	0.020
	0.405	0.380	0.025	0.001	0.039
	0.405	0.375	0.030	0.001	0.039
	0.337	0.315	0.022	0.000	0.017
	0.187	0.212	−0.025	0.001	0.000
	0.140	0.160	−0.020	0.000	0.005
	0.112	0.125	−0.013	0.000	0.009
	0.062	0.075	−0.013	0.000	0.021
	0.000	0.000	0.000	0.000	0.043
Average	0.208		Sum	0.006	0.249
C.S 3	0.000	0.000	0.000	0.000	0.098	0.976
	0.055	0.112	−0.057	0.003	0.066
	0.187	0.250	−0.063	0.004	0.016
	0.475	0.430	0.045	0.002	0.026
	0.612	0.595	0.017	0.000	0.090
	0.590	0.595	−0.005	0.000	0.077
	0.537	0.562	−0.025	0.001	0.050
	0.450	0.480	−0.030	0.001	0.019
	0.395	0.420	−0.025	0.001	0.007
	0.350	0.390	−0.040	0.002	0.001
	0.312	0.325	−0.013	0.000	0.000
	0.250	0.245	0.005	0.000	0.004
	0.160	0.120	0.040	0.002	0.023
	0.000	0.000	0.000	0.000	0.098
Average	0.312		Sum	0.015	0.575

Fig. 7 Model arrangements (existing situation).

Fig. 8 Model arrangements (first modification).

Fig. 9 Model arrangements (second modification).

Fig. 10 Model arrangements (third modification).

Fig. 11 Model arrangements (fourth modification).

Fig. 12 Velocity distribution at C.S.1.

Fig. 13 Velocity distribution at C.S.2.

Fig. 14 Velocity distribution at C.S.3.

Fig. 15 Discharges passed from NHPS units (all modification).

Table 4 Summary of the four complementary modifications.

Mod. no.	Modification type	Modification size	(Q passed from NHPS units) (numbered from the left bank)
			1	2	3	4	5	Sum
Current			8.6	8.6	8.2	6.8	4.4	36.5
1	Dredging sedimentation and remains of the removed bridge upstream of NHPS.	Bed levels became −5.5 m instead of −4.5 m (for 50 m)	8.2	8	7.75	6.25	5.6	35.8
	Rehabilitation of the side slope of NHPS channel left bank	Side slope became 2:1 instead of 3:1 (for 50 m)
2	Continue dredging the sedimentation upstream of NHPS.	Bed levels became −6 m instead of −5.5 m (for 100 m)	8.1	8.35	7	6.5	6.2	36.15
	Continue rehabilitation of the side slope of NHPS channel left bank	Side slope became 2:1 instead of 3:1 (for 100 m)
	Shifting the toe of the embankment, between the two stations	Shifting the toe 2 m towards OHPS
3	Installing Spur Dykes at HSD right bank	3 Spur Dykes with angle of 75° with HSD right bank	8.1	8.3	7.4	7.5	6.8	38
		Lengths = 2, 7 and 12 m measured from contour line of level −2 m on the right bank
		Distance from the axis of the removed bridge = 12, 24 and 36 m
4	Creating humps in HSD bed downstream of the installed Spur Dykes at location near the outer bank of NHPS channel	2 Humps, one with level of −5.25 m and width 30 cm width	8	8.1	7.85	7.65	7.45	39.05
		The second with level-5.5 m level and width 50 cm