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Université Mohamed Khider - BISKRA - ALGERIALaboratoire Aménagements Hydrauliques et Environnement
Tel/Fax : (+213) 033 73 79 62 Mobile : (+213) 062 57 31 24 Email : [email protected]
Paris - Chatou, France 20-22 November 2013
2nd International Workshop on Labyrinth and Piano Key Weirs
Présenté par :- Prof . A.Ouamane
- Mr. F. Belaabed
Submerged flow regimes of PK-Weir
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
SommaireSommaire
I. Introduction
II. Experimental program
III. Experimental results
Submerged flow regimes of PK-Weir
1- Effect of the discharge on the submergence of the PK-Weir
2- Comparison of the results obtained on the different models
3- Mathematical relationship of the coefficient of submergence
IV. Conclusion
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
I. Introduction
The spillway is regarded as one of the most important hydraulic
infrastructures; this returns to its multifunction, it is often used as
component of discharge control and spillway in the rivers. It can be
Submerged flow regimes of PK-Weir
designed in several forms depending on the characteristics
required, namely, the dimensions and the profile of the cross-section, the
shape of the indentation, the provision in relation to the direction of
flow, and the upstream and downstream conditions of the flow.
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
Based on these last; there are two types of weirs according to
the conditions of their operation. The first type corresponds to the
free flow weir when water level the downstream does not influence
on the flow to the upstream, as well, the aquifer is assumed to be
free (figure 1-a).
Submerged flow regimes of PK-Weir
( g )
The second type corresponds to the submerged weir when the
water level downstream affects the water level upstream (figure 1-b).
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
a- Free flow b- Submerged flow
Submerged flow regimes of PK-Weir
Figure 1. Definition of hydraulic parameters for the weir under free and submerged flow conditions
� Submerged flow - H*: upstream total head; - h*: upstream piezometric head;- Hd: downstream total head; - hd: downstream piezometric head.
� Free flow- Ho: upstream total head; - ho: upstream piezometric head.
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
Piezomere Flowmeter 93W2Gate
Submerged flow regimes of PK-Weir
Figure 2. The experimental facility
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
�� Model of weirModel of weir
Submerged flow regimes of PK-Weir
Figure 3. Model of PK-Weir
a- PK-Weir type A2m b- PK-Weir type A1
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
Table 1. Geometrical characteristics of the experimented model
Model of weir n0 n Lcm
Wcm
W0cmWicm
Bcm
B0cmBicm
BbcmP0=Picm
PK-Weir model APK-Weir model A
A2mA1
1.53
266197
6633
189.5
157
4741
1210.25
1210.25
2320.5
2015
Submerged flow regimes of PK-Weir
a- Plan view b- Cross section
Figure 4. Geometrical configuration of the model A1
a- Plan view b- Cross section
Figure 5. Geometrical configuration of the model A2m
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
Wc
� Experimental installations according to the upstream conditions
Submerged flow regimes of PK-Weir
Wt
Figure 6. PK-Weir with lateral contraction
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
II Experimental program
Sill
Submerged flow regimes of PK-Weir
Figure 7. Experimental program
Q 1PK-Weir
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
a- Phase free flow
hd
h*
h*
hd
III Experimental results
Submerged flow regimes of PK-Weir
Figure 8 : Different phases of the flow on the PK-Weir
b- Phase transition
c- Phase submerged flow
h*hd
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
1.5
2
2.5
3
H*/
H0
1- Effect of the discharge on the submergence of the PK-Weir1-1 Effect of the discharge on the submergence of the PK-Weir A2m
a- Phase free flow
Submerged flow regimes of PK-Weir
Figure 9. Relative upstream head according relative downstream head (model type A2m)
0
0.5
1
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3
H
Hd/H0
PK-Weir A2m Q=30.84l/sQ=46.05l/sQ=60.69l/sQ=75.31l/sQ=90.82l/s
Q=104.76l/sQ=120.67l/sQ=141.01l/s
b- Phase transition
c- Phase submerged flowI II III
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
1-2 Effect of the discharge on the submergence of the PK-Weir A1
Submerged flow regimes of PK-Weir
Figure 10. Relative upstream head according relative downstream head (model type A1)
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
2- Comparison of the results obtained on the different models
1
1.5
2
2.5
3
H*/
H0
Submerged flow regimes of PK-Weir
Figure 11. Comparison of the effect of submergence between the PK-Weir type A2m , A1 and model PK-Weir (Tullis 2012)
0
0.5
1
0 0.5 1 1.5 2 2.5 3
Hd/H0
PK-Weir A1 Q=142.28l/s
PK-Weir A2m Q=141.01l/s
Courbe de référence PK-Weir (Tullis 2012)
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
3- Mathematical relationship of the coefficient of submergence
Submerged flow regimes of PK-Weir
Figure 12. Discharge for submerged Weir
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
� Rectangular Weir (Villemonte) :
� PK-Weir type A2m :
Submerged flow regimes of PK-Weir
� PK-Weir type A (Results of physical models HCM) :
��������d��������
��������d��������
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
IV. Conclusion
This study is primarily interested in the effect of the downstream level
on the upstream level in submerged flow conditions. The tests carried out
on two models of PK-Weir have shown that the downstream conditions
can affect the upstream flow of the PK-Weir. This influence has been
demonstrated that it is characterized by a proportional variation between the
Submerged flow regimes of PK-Weir
y p p
upstream and the downstream whatever the importance of the discharge. It
was also found that the variation of the relative downstream head compared to
the relative upstream head is done in a proportional manner for the
different discharge on the PK-Weir A2m.
2nd International Workshop on Labyrinth and Piano Key Weirs Paris - Chatou, France 20-22 November 2013
The PK-Weir with overhangs continued up to the base (A2m)
seems to be more exposed to the submergence that the PK-Weir standard
type A.
The PK-Weir has the advantage to be better adapted to function
Submerged flow regimes of PK-Weir
in conditions of submerged flow, however, the linear weir is more
susceptible to submergence. As well, the importance of the effect of the
submergence depends on the type of weir.
Université Mohamed Khider - BISKRA - ALGERIALaboratoire Aménagements Hydrauliques et Environnement
Tel/Fax : 033 73 79 62 Mobile : 062 57 31 24 Email : [email protected]