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A new type of hydraulic ram pump, called "Raseta pump", was invented, patented and crafted in Madagascar. The peculiarity of this hydram pump over conventional ones is that there is a spring in each of the waste and delivery valves. In addition, the usual air balloon is replaced by a balloon with 4 springs. Thus, this paper aims at theoretically studying the behaviour of this hydram pump equipped with a system of springs. For that purpose, a model associated with the studied hydram pump was developed and coded on Matlab. Then, a global sensitivity analysis was carried out for identifying the most influential parameters of this model while successively considering as the surveyed model outputs: the amount of wasted water, the amount of pumped water and the efficiency of the pump. As results, the most dominating parameters are relatively the same as those found by previous works on the conventional hydram pump without springs: height of the water column in the delivery pipe, the height of supply tank, the weight of the waste valve, and the length of the waste valve stroke. However, there are 3 other parameters that the present study exceptionally found as among the most influential ones as well, namely: the stiffness of the spring in the waste valve, the modulus of elasticity of the fluid, and the radius of the waste valve disk. In addition, similar to the case of air balloon, the effect of the spring balloon is not relevant. An extension work could be a techno-economic investigation of a pump system constituted by a number of hydram pumps similar to the one studied here for increasing water head in a pico hydropower plant.
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American Journal of Fluid Dynamics 2019, 9(1): 1-12
DOI: 10.5923/j.ajfd.20190901.01
Theoretical Study of the Behavior of a Hydraulic Ram
Pump with Springs System
Andriamahefasoa Rajaonison*, Hery Tiana Rakotondramiarana
Institute for the Management of Energy (IME), University of Antananarivo, Antananarivo, Madagascar
Abstract A new type of hydraulic ram pump, called "Raseta pump", was invented, patented and crafted in Madagascar.
The peculiarity of this hydram pump over conventional ones is that there is a spring in each of the waste and delivery valves.
In addition, the usual air balloon is replaced by a balloon with 4 springs. Thus, this paper aims at theoretically studying the
behaviour of this hydram pump equipped with a system of springs. For that purpose, a model associated with the studied
hydram pump was developed and coded on Matlab. Then, a global sensitivity analysis was carried out for identifying the
most influential parameters of this model while successively considering as the surveyed model outputs: the amount of
wasted water, the amount of pumped water and the efficiency of the pump. As results, the most dominating parameters are
relatively the same as those found by previous works on the conventional hydram pump without springs: height of the water
column in the delivery pipe, the height of supply tank, the weight of the waste valve, and the length of the waste valve stroke.
However, there are 3 other parameters that the present study exceptionally found as among the most influential ones as well,
namely: the stiffness of the spring in the waste valve, the modulus of elasticity of the fluid, and the radius of the waste valve
disk. In addition, similar to the case of air balloon, the effect of the spring balloon is not relevant. An extension work could be
a techno-economic investigation of a pump system constituted by a number of hydram pumps similar to the one studied here
for increasing water head in a pico hydropower plant.
Keywords Hydram pump, Water supply, Bernoulli equation, Raseta pump, Modelling, Global sensitivity analysis
1. Introduction
The hydraulic ram pump, which is simply called hydram
pump from now on, was invented by Joseph Michel
Montgolfier by the end of the 18th century [1]. Used as a
water supply machine, this pump uses the energy of water
to raise a certain water amount to a height much higher than
that of the initial watercourse [1]. This process is based on a
phenomenon known as "water hammer" [2] which is a
shock wave created by the sudden stop of moving water [3].
In other words, the kinetic energy of a water column having
taken a certain speed is stopped suddenly by a valve which
creates an overpressure [4, 5]. This harmful phenomenon
for pipelines [6] is used in the hydram pump to raise water
without any other source of energy than that of the water
itself [7].
Several studies were carried out on hydram pump which
generally has six main components [5, 8, 9] as can be seen
from Figure 1.
* Corresponding author:
rajmahefasoa@gmail.com (Andriamahefasoa Rajaonison)
Published online at http://journal.sapub.org/ajfd
Copyright © 2019 The Author(s). Published by Scientific & Academic Publishing
This work is licensed under the Creative Commons Attribution International
License (CC BY). http://creativecommons.org/licenses/by/4.0/
Figure 1. Components of a conventional hydram pump
With the hydram pump configuration shown in Figure (1),
Lansford and Dugan [1] carried out a rational mathematical
analysis of the operation of hydram pumps and compared
the results with those obtained from experimental survey
conducted on two pumps with different supply pipe
diameters. They considered the effects of the elasticity of the
impulse valve disc and the pumping was carried out by
several fast pressure waves or pulses of water in the
discharge pipe during the pumping period. The pumping
2 Andriamahefasoa Rajaonison et al.: Theoretical Study of the
Behavior of a Hydraulic Ram Pump with Springs System
cycle was then divided into six distinct periods and the
relationship between speed and time for the water column in
the supply pipe during each part of the cycle was determined.
It was concluded that the height of the discharge tank and
the speed required to start closing the water valve have
significant effects on the amount of pumped water and lost
water per cycle as well as the cycle time. More precisely, it
was found that, for discharge pressures less than half the
maximum pressure that can be developed by the hydram
pump, the amounts of pumped water and lost water per cycle
can respectively be predicted with an error of less than 10%,
for a particular setting of the ram valve. The values given by
the mathematical results are much closer to the experimental
values for the largest ram. Meanwhile, Gibson [4] considered
a cycle in four periods and showed that the amount of lost
water mostly depends on the mass and the stroke of the waste
valve, the ratio between the length of the supply pipe, and the
height of the supply tank while Young [9] asserts that this
last parameter affects only the total duration of a cycle. The
pump capacity and efficiency are influenced by: the waste
valve surface, the delivery height, the ratio of the delivery
height to the supply height, and the ratio between the length
of the supply pipe and the height of the supply tank.
According to Gibson [4], the area of the waste valve is the
most important source of loss and contributes between 15
and 25% of the total energy received by the pump. It was also
showed that it is impossible to pump at a delivery height
greater than about six times the supply height. Another study
on the hydram pump was conducted by Kahangire [5] in
which friction losses are considered. Flux returns and the
effects of the elasticity of valve materials are neglected. The
pumping cycle is divided into four main periods, based on
the position of the waste valve and the average time-velocity
variation in the supply pipe. The developed model is
based on the following assumptions: an one-dimensional
approximate equation of steady flow is applied for flow in
the supply pipe; the parameters determined under constant
flow conditions are approximately constant; the closing of
the waste valve is instantaneous; the water velocities in the
supply pipe when the waste valve begins to close and is
finally closed are the same; the resistance due to the
movement of the spindle through the valve guide is
negligible and constant; only the changes of the flow average
speed and the pressure difference in the system are taken into
account. Kahangire [5] mentions that pump efficiency,
pumped water flow and pump power are influenced by: the
length of the supply pipe [8, 10]; length of stroke, mass and
size of the waste valve; and finally, the supply height [11].
For the air chamber, its volume has no significant effect on
the operating characteristics of the pump but may be
necessary to absorb the increased pressures that occur in the
pump [5]. Inthachot et al. [12] aimed to build a reliable and
cheap ram made of commercially available parts and
available locally. They were able to deduce that from a
certain size; the volume of the air chamber is not crucial for
the operation of the ram. Each valve had a different spring,
and both show that the tension of their springs greatly
influences the performance of the pump [12]. For Deo et al.
[13] they presented a design methodology of the pump by
doing an analysis on the ANSYS (Computational Fluid
Dynamics) CFD- FLUENT R14.5software [14]. They
concluded that the parameters that are essential for the
efficiency and design of the pump are: the static pressure in
the supply head, the diameter of the supply pipe [15], the size
of the air chamber, and the waste valve [13, 16]. Girish et al.
[17] have done a study of the pump to analyse the flow and
the height of the delivery. They have shown that flow and
head are strongly influenced by: the height, length and
diameter of the supply pipe [15, 18], and the discharge pipe.
As before the chamber eliminates the sound of water
hammers [17]. In addition, Hussin et al. [19] analysed and
developed a ram pump to achieve a desired delivery height of
up to 3 meters with reduced operating cost. The simulation
was performed using the ANSYS CFX R15.0 software [20].
The results of this study show the diameter of the air
chamber is critical to increase the water pressure. In addition,
the supply height and the amount of water at the source play
a vital role in the system [19].
In summary, it has been shown that the efficiency of the
pump is intrinsically linked to the supply height, the stroke
and the mass of the waste valve, the volume of the air
chamber [21] and finally the height of the delivery tank.
At my present state of knowledge, no study has been
conducted on the modelling of a hydram pump with a spring
system at the waste valve and the delivery valve. As for the
air chamber equipping the conventional hydram pump, it is
replaced by a balloon with 4 springs attached to a valve at
their ends (Figure 3).
Thus, the objective of the present work is firstly to develop
a model of this hydram pump with spring system then to
carry out a global sensitivity analysis of the abovementioned
model.
2. Materials and Methods
2.1. Description of the Functioning of Hydram Pump
System to Model
Figure 2. Overview of the pumping system
American Journal of Fluid Dynamics 2019, 9(1): 1-12 3
Figure 3. Scheme of the studied hydram pump with system of springs [22]
The hydram is fed by a source which is a tank or
stabilization tank itself fed by a river, a watercourse, etc. The
pumped water is then stored in a tank for later use (Figure 2).
The operation of the pump can be described in a cycle of 6
periods [1] (Figure 4).
Figure 4. Functioning of the studied hydram pump
Period 1 is the time during which the waste valve begins to
close until it is completely closed [5, 7, 12] (Figure 4a)
(Figure 4b). Then, in period 2 is the moment between the full
closure of the waste valve and the opening moment of the
delivery valve [21] (Figure 4c). The third period is the time
during which the delivery valve remains open [5, 21] (Figure
4d). This is followed by the fourth period, which is the time
between the closing of the delivery valve and the beginning
of the opening of the waste valve [21] (Figure 4e). Then
during period 5, it is the time between the beginning of the
opening of the waste valve and the start of the water loss
(Figure 4e and Figure 4f). And finally, during period 6, it is
the time between the beginning of losses and the moment
when the waste valve starts to close (figure 4g). Once the
sixth period is over, the cycle restarts.
2.2. Mathematical Formulation
A step-by-step analysis will assist in establishing the
model that gives the amount of lost water, the amount of
pumped water per cycle, and the efficiency of the hydram
pump.
2.2.1. Simplifying Assumptions
The following simplifying assumptions are adopted for
modelling the studied hydram pump:
I. The quantity of water in the supply tank is constant,
that is, the flow of water entering it from a river, or
any other form of watercourse is greater than the
flow of water coming out through the supply pipe.
An overflow is also installed.
II. The waste valve is assumed to be elastic [1].
III. The 4 springs in the balloon are identical and the sum
of their masses is neglected.
IV. The initial position of the valve in the balloon is at
the same level as that of the waste valve.
V. The weight of the delivery valve is negligible
compared to the return force of its spring.
VI. The supply pipe has no obstacle such as a fitting, a
bend or other obstacles. The head loss in the supply
pipe is only due to the roughness of the pipe.
VII. In the study of period 2, the friction in the supply
pipe is neglected because the pressure change caused
by this friction is not significant compared to the
other pressure changes for a well installed pump [1].
VIII. The waste valve disk is considered to be a circular
plate whose bending is assumed as being due to a
point load applied to its centre.
IX. The disk of the waste valve is assumed to rest all
around its circumference.
X. Frictions during study of period 5 are neglected [1]
XI. The valve attached to the ends of the springs in the
balloon is well sealed so that no water can overflow
outside during operation of the studied hydram
pump.
XII. The air in the balloon containing the four springs is
in contact with the outside air.
XIII. The head loss at the elbow at the base of the
hydram pump is neglected.
XIV. The relaxation of the springs in the balloon at the end
4 Andriamahefasoa Rajaonison et al.: Theoretical Study of the
Behavior of a Hydraulic Ram Pump with Springs System
of the period 3 is instantaneous and, therefore, does
not influence the duration of a cycle.
2.2.2. Mathematical Model Relating to Period 1
Period 1 represents the duration (s) of the closure of the
waste valve [21] and is determined by equation (1):
3
1
wH
v
A2
c
r2 Lb4
i
k1
v
M
1H
2
g4
w
v
Ag
v
M
0
SL
1
t
(
(1)
02540 0
S
856520
10
02540 0
S
27503450
0
S
02540 .
..
.
..
.
[21] (2)
In addition, apart from the nomenclature given in the
appendix 1, b represents, in equation (1), the linear head loss
coefficient of the supply pipe (-). More precisely, b can be
calculated with the help of the formula of Poiseuille, Blasius
or Blench according to the flow regime in the supply pipe
[18, 23, 24, 25, 26]; hence, the calculation of b requires the
knowledge of the value of the water minimum velocity v0 at
which the waste valve begins to close (m.s-1) [21] and which
can be computed by equation (3) :
cs
Hg2
0
v
(3)
02540 0
S
3013950
10
02540 0
S
061432
0
S
02540
c.
..
.
..
.
[1, 21] (4)
v
Aw v
M
s
H
[9, 27] (5)
with
(6)
Figure 5. Forces applied on the waste valve
in which F1 represents the sum of the forces exerted on the
waste valve (Figure 5), and is expressed by equation (7):
cosg
1
M
0
S
1
k
1
F
(7)
It can be seen from equation (1) that the waste valve
cannot close if the denominator is equal to zero [21]; as a
result, the equivalent weight of the waste valve must meet
the following condition:
c
r2 Lb4
i
k1
wH
v
A2
v
M
(8)
The water velocity in the supply pipe v1 (m.s-1) at the end
of period 1 is given by equation (9) [1]:
21
t
6
0
v
1
v
(9)
L2j
2
0
v
jHg2
6
[1] (10)
where
1cbj
(11)
It worth noting that the waste valve will not close either if
α6 does not meet the condition (12):
0
6
(12)
equations (3), (10) and (12) give the minimum height of the
supply tank meeting the closure condition of the waste valve,
and can be determined as follows:
cs
Hj
H
(13)
The amount of lost water during period 1 can be computed
by equation (14) [1]:
3
2
1
t
6
1
t
0
vAw
1
Q
(14)
2.2.3. Mathematical Model Relating to Period 2
The duration of period 2 can be computed as follows [1]:
2
v1
v
LogZ
2
t
(15)
where
v
EgA
2
v
Awa
Z
(16)
Ew
K2
1w
K
a
[8, 28] (17)
 
r2
u
11
r2
u
2
4
5
r2
u
11
[28] (18)
f
F
v
E
[29, 30, 31] (19)
American Journal of Fluid Dynamics 2019, 9(1): 1-12 5
3
eE
2
v
rF
1
3
2
1
4
3
f
[31] (20)
v
1
v
2
v
[1] (21)
According to equation (21) the delivery valve will not
open if
1
vv
(22)
ag
0
h
v
[1] (23)
 
 
g4 v1
vm
Hh
0
h
[1] (24)
This expression of h0 of Lansford and Dugan [1] is the
expression of a delivery valve without spring; thus, in the
present case, we have to consider an additional load which is
the height of the water column (ha) necessary to oppose the
pressure force of the delivery spring for a full opening.
Hence, equations (24) and (23) become respectively
 
a
h
g4 v
1
vm
Hh
0
h
(25)
where
2
r
rgw
1
S
2
k
a
h
(26)
Therefore, equations (23) and (25) give:
g4 1
vm
2
r
rgw
1
S
2
k
Hh
ma4 g4
v
(27)
Equations (22) and (27) define the conditions of the
stiffness k2 of the delivery valve spring for the opening of
this valve, that is:
 
g4 1
vm
Hh
g4 ma4
1
v
1
S
2
r
rgw
2
k0
(28)
2.2.4. Mathematical Model Relating to Period 3
It is during the third period that the water is pumped.
However, the pumping of water is not done in one go or
continuously but by discontinuous pushes induced by
pressure waves. The water velocity in the supply pipe
gradually decreases until the water can no longer be pumped
through the delivery pipe [1].
The duration of period 3 can be computed as follows [1]:
r
t
2
t
aN
1
L2
3
t
(29)
r
v
1
v2 1
v2
LogZ
r
t
[1] (30)
 
v1N2
1
v
r
v
[1] (31)
In which, N is an integer and denotes the number of pushes
between period 2 and period 3 as defined by the following
condition [1]:
v2 v
1
v
N
v2 v
1
v
(32)
At the end of period 3 the water velocity is defined as [1]:
vN2
1
v
3
v
(33)
The value of v3 can be either positive or negative
according to the sense of the water flow.
The amount of pumped water qs during this third period is
given by equation (34) [1]:
   
 
r
t
r
v
1
v2
2
t
1
v1N
2
tv
2
1Ntv
2
N
r
vZvZ1N2t
1
vNAw
s
q
''
(34)
where
2
t
a1
L2
t'
(35)
2.2.5. Modeling of the Spring Balloon
The previous study of period 3 does not take into account
the spring balloon. Thus, a modeling procedure similar to an
air balloon proposed by Krol [10, 21] was adopted for the
modeling of our spring balloon. During period 3, water is
temporarily stored in the balloon [10, 21] before being
ejected into the delivery pipe. In order to compute this
amount of additional pumped water, the level of water in the
spring balloon should first be known by means of the
following energy balance [21]:
3
E
2
E
1
E
0
E
(36)
The energy received by the balloon is given by equation
(37) [21]:
 
 
c
hH
T
3
t
1
s
q
r
hHh
s
q
0
E
(37)
Where, hr is the sum of the head losses during period 3 (m)
and is given by equation (38):
el
h
red
h
d
h
v
h
s
h
r
h
(38)
A head loss can be linear or singular [16, 18, 23, 25, 26,
32], if for the case of linear it is calculated as b otherwise it
will depend on the nature of the singularity.
hred is the singular head loss by the progressive reduction
of the pipe (m) (Figure 6), its head loss coefficient kred [33] is
determined as followed:
2
2
for
2
1
1
2
2
for
2
2
1
1
red
k
,
,sin
(39)
where θ2 represents the solid angle in the shrinkage in degree
(Figure 6).
3
A
red
A
370630
..
(40)
6 Andriamahefasoa Rajaonison et al.: Theoretical Study of the
Behavior of a Hydraulic Ram Pump with Springs System
Figure 6. Progressive shrinkage of the supply pipe
And hel is the singular head loss by progressive expansion
of the pipe (m) (Figure 7), its head loss coefficient kel [34, 35]
is given by equation (41):
2
2
b
r2 3
r2
1
251
2
023
el
k
.
tan.
(41)
As χ is the angle at the enlargement (degree) see Figure 7.
Figure 7. Gradual enlargement of the pipe
The energy lost in the supply pipe and in the delivery
valve is given by equation (42) [21]:
 
v
h
s
h
s
q
1
E
(42)
The energy of the water directly pumped on the head (h +
hd) is given by equation (43) [21]:
 
d
hh
T
3
t
s
q
3
E
(43)
The isothermal compression for a conventional hydram
pump is, in the present study, replaced by the potential
energy due to compression of the four springs which is
computed by equation (44):
c
h
2
M
2
c
h
3
kg4
2
1
2
E
(44)
Equation (36) then becomes:
 
 
 
d
hh
T
3
t
s
q
c
h
2
M
2
c
h
3
kg4
2
1
v
h
s
h
s
q
c
hH
T
3
t
1
s
q
r
hHh
s
q
(45)
By resolving equation (45), one can get the value of hc
enabling to compute the potential energy stored in the spring
balloon which is then converted into kinetic energy at the end
of period 3.
While using the principal of mechanical energy
conservation, the velocity of the spring balloon membrane at
the end of period 3 can be obtained:
2
Mc
hg
2
M2
2
c
h
3
k4
f
v
(46)
This velocity of the membrane is taken as the velocity of
the water at the spring balloon, which makes it possible to
determine the velocity of the water at the exit of the delivery
pipe at a height h and thus, to deduce the amount of extra
pumped water qsup.
To determine the water velocity at the outlet of the
delivery pipe, we adopted the Bernoulli equation [36, 37]
which is related to a stationary and steady flow of an
incompressible real liquid without energy exchange between
two points, denoted A and B, along an axis noted (S), as
shown in the Figure 8 [24, 32].
Figure 8. Elevation of water along the delivery pipe during the thrust of
the balloon membrane
It follows from the resolution of the Bernoulli equation
between two points A and B that the water velocity at B is
given by:
otherwise0
0
2
r2 2
L
1if
2
1
2
r2 2
L
1
f
v
B
v
,
,
(47)
Then, the quantity of extra pumped water is:
w
B
v
2
2
r
sup
q
(48)
2.2.6. Mathematical Model Relating to Period 4
The duration of period 4 is given by equation (49) [1]:
American Journal of Fluid Dynamics 2019, 9(1): 1-12 7
0
3
vif,
a1
L2
3
v
4
vvZ2
4
t
0
3
vif,
4
v
3
vvZ2
4
t
(49)
 
L
2
vZa
2
3
v
4
v
(50)
2.2.7. Mathematical Model Relating to Period 5
The friction is neglected during this period because they
have little influence on the values of the duration and the
velocity of the water. Then, the duration of period 5 [1] is
computed with equation (51):
Hg 4
vL2
Hg 5
vL2
5
t
(51)
4
v
5
v
[1] (52)
2.2.8. Mathematical Model Relating to Period 6
Equation (53) enables to calculate the duration of period 6
[1]:
5
v
jHg2
5
v
jHg2
0
v
jHg2
0
v
jHg2
Log
jHg2
j
L
6
t
(53)
The velocity of water in the supply pipe during the last
period is the same as of the minimum velocity to begin the
closure of the waste valve.
The amount of water lost during period 6 is given by
equation (54) [1]:
2
0
v
jHg2
2
5
v
jHg2
Log
jLAw
6
Q
(54)
Thus, the duration of a complete cycle of the hydram
pump is:
6
t
5
t
4
t
3
t
2
t
1
tT
(55)
The amount of lost water Q per cycle can be computed as
follows [1]:
T6
Q
1
Q
Q
(56)
The amount of pumped water q per cycle is determined
with equation (57):
sup
q
T
s
q
q
(57)
And the efficiency of the studied hydram pump can then
be determined by the Rankine formula [1, 5, 8, 10].
2.3. Calculation Procedure
Figure 9 presents the successive steps for the calculation
procedure:
Figure 9. Successive steps for the calculation procedure
8 Andriamahefasoa Rajaonison et al.: Theoretical Study of the
Behavior of a Hydraulic Ram Pump with Springs System
2.4. Work Tools
The model associated with the studied system was coded
on Matlab [38] while the global sensitivity analysis of this
model was conducted with the help of a Matlab coded tool
named GoSAT (Global sensitivity analysis tool) [39] which
is an algorithm using a derived method FAST (Fourier
Amplitude Sensitivity Test) for automatically ranking in
downward order in a bar chart the main effects and the
second interaction effects of various parameters of a model
[40]. In the present work, 3 model outputs were successively
surveyed, namely: the amount of pumped water, the amount
of lost water and the efficiency of the hydram pump; while
inputting 31 parameters for each surveyed model output.
3. Results and Discussion
3.1. Adequate Stiffness Values of the Delivery Valve
Spring and the Balloon Springs
Before carrying out the global sensitivity analysis of the
model, the ideal value ranges of stiffness of the delivery
valve spring and the balloon springs are determined. While
taking the stroke length of the waste valve S0 equal to 0.002
(m), its spring stiffness k1 equal to 100 (N.m-1) and the value
of the balloon membrane stroke S2 equal to 0.15 (m), the
values of k2 and k3 were respectively varied between [0, 6500]
and [0, 3], we computed the water height in the balloon of
which contours are presented in Figure 10 according to
values of k2 and k3. In fact, the value ranges of these two
parameters have to be chosen such that the level of water in
the balloon should not exceed the stroke length of the valve
in the balloon.
As can be seen from Figure 10, the suitable value ranges of
k2 and k3 that meet the abovementioned condition are
respectively [0, 100] and [0.5, 2].
Figure 10. Contours of water height in the balloon according to the values
of k2 and k3
3.2. Results of the Global Sensitivity Analysis of the
Developed Model
Figures 11, 12 and 13 present the most influential
parameters of the developed model while respectively taking
the amount of pumped water, the amount of lost water, and
the hydram pump efficiency as surveyed model outputs.
Figure 11. Classification of the most dominating factors of the model,
pumped water
Figure 12. Classification of the most dominant factors of the model, lost
water
Figure 13. Ranking of the most dominant factors of the model, efficiency
American Journal of Fluid Dynamics 2019, 9(1): 1-12 9
Firstly, from section 2.2. Mathematical formulation, 31
parameters are considered in the global sensitivity analysis
of the developed model. Then, for both Figures 11, 12, and
13 the parameters on the left are those having a negative
effect on the surveyed model output and those on the right
have positive effect on this output [40].
As can be seen from Figures 11, 12, and 13 the most
influential parameters for the amount of pumped water, for
the amount of lost water and for the efficiency of the hydram
pump are quite the same, namely:
- the length of the waste valve stroke, S0
- the radius of the waste valve disc, rv
- the stiffness of the waste valve spring, k1
- the height of the water column in the delivery pipe, h
- the waste valve weight, M1
However, apart from those parameters, if one wants to act
specifically on the amount of pumped water it is necessary to
consider, firstly, the supply tank height, H and then, the
supply pipe radius, r (Figure 11), if the latter goes first for the
amount of lost water (Figure 12). On the other hand, if one
wants to influence more on the efficiency of the hydram
pump, 3 other parameters should be taken into account,
namely: the length of the supply pipe from the source to the
center of the delivery valve, L1; the length of the supply pipe
from the source to the center of the waste valve, L; and the
slope of the hydram pump relative to the horizontal, θ
(Figure 13).
4. Conclusions
After modelling and the sensitivity analysis of the
parameters of the hydraulic ram pump with springs system,
the parameters which influence both the amount of pumped
water, the amount of lost water and the efficiency of the
pump are the same, namely: the length of the waste valve
stroke; the radius of the waste valve disc, the stiffness of the
waste valve spring, the height of the water column in the
delivery pipe, and the waste valve weight.
These results are the same as those of previous studies on
the hydraulic ram pump [1, 9, 21]. But if it has been shown
that the weight of the waste valve plays an important role on
the operation of the pump, this parameter is less important
than the stiffness of the waste valve spring in our case.
Therefore, if one wants to have good results for each
output independently, it is necessary to act on additional
parameters. Those parameters are the same for the amount of
pumped and lost water which are: the supply tank height and
the supply pipe radius as shown in Figures 11 and 12. For the
efficiency of the pump, those parameters are: the length of
the supply pipe from the source to the center of the delivery
valve, the length of the supply pipe from the source to the
center of the waste valve, and the slope of the hydram pump
relative to the horizontal as shown in Figure 13.
As for the balloon containing the four springs, it was
shown that it has no influence on the operation of the pump.
Indeed, for a classic hydram pump with an air balloon,
previous study deduced that compared to the kinetic energy
in the supply pipe, the potential energy due to the balloon
effect is small and may be neglected [21]. So, as obtained
from the global sensitivity analysis of the model, the spring
balloon has no effect on the operation of the studied hydram
pump. In fact, the balloon is mainly used only to eliminate
the noise of the water hammer [17, 41].
The studied spring hydram pump was invented and crafted
in Madagascar by Rasetarivelo who applied a patent at the
Malagasy Office of Industrial Property (OMAPI) in 2004;
the patent is entitled "Pompe à eau à système de ressorts sans
autre source d’énergie que l’eau" (hydram pump with springs
system without any other source of energy but water), and
the application number is 2004/012 [22].
As a follow-up to this study, the techno-economic aspect
of the pump could be interesting in case of a small
hydropower plant to increase water head. Moreover, a
comparison between experimental and simulation results can
be carried out too.
Nomenclature
a : velocity of pressure-wave transmission in the
supply pipe (m.s-1), given by equation (17)
A : cross section of the supply pipe (m2)
Av : area of the waste valve (m2)
Ared : cross section of the shrinked pipe (m2)
b : linear head loss coefficient of the supply pipe (-)
c : friction coefficient of the waste valve (-), given by
equation (4)
e : thickness of the disk of the waste valve (m)
E : modulus of elasticity or Young's modulus of the
supply pipe (N.m-2)
E0 : energy received by the balloon (kg.m), given by
equation (37)
E1 : energy lost in the supply pipe and in the delivery
valve (kg.m), given by equation (42)
E2 : potential energy due to the compression of the four
springs (kg.m), given by equation (44)
E3 : energy of the water directly pumped on the head
(h+hd) (kg.m), given by equation (43)
Ev : average stiffness of the waste valve disc (kg.m-1),
given by the equation (19)
f : bending of the disk of the waste valve (m), given
by equation (20)
F : point charge (N)
F1 : sum of the forces exerted on the waste valve (N),
given by equation (7)
g : acceleration of gravity (m.s-2)
h : height of the water column in the delivery pipe (m)
h0 : increase of the pressure head necessary to open the
delivery valve (m), given by equation (25)
hc : level of water in the balloon (m)
hd : linear head loss in the delivery pipe during period
3 (m)
10 Andriamahefasoa Rajaonison et al.: Theoretical Study of the
Behavior of a Hydraulic Ram Pump with Springs System
hel : singular head loss by progressive expansion of the
pipe (m)
hs : head loss in the supply pipe during the period 3
(m)
hv : singular head loss due to the delivery valve during
period 3 (m)
ha : height of the water column necessary to oppose the
pressure force of the delivery spring for a full
opening (m), given by equation (26)
hred : singular head loss by the progressive reduction of
the pipe (m)
hr : the sum of the head losses during period 3 (m),
given by (38)
H : height of the supply tank (m)
Hs : static head for closing of the waste valve (m),
given by equation (5)
k1 : spring stiffness constant of the waste valve (N.m-1)
k2 : spring stiffness constant of the delivery valve
(N.m-1)
k3 : stiffness of each spring in the spring balloon
(N.m-1)
ki : sum of the singular head loss coefficients due to
obstacles: fitting, elbow and others (-)
ks : coefficient de perte de charge de la conduite
d’alimentation (-)
K : modulus of elasticity of water (N.m-2)
kel : head loss coefficient by progressive expansion of
the pipe (-), given by equation (41)
kred : head loss coefficient by the progressive reduction
of the pipe (-), given by equation (39)
L : length of the supply pipe from the supply tank to
the center of the waste valve (m)
L1 : length of the supply pipe from the source to the
center of the delivery valve (m)
L2 : length of the delivery pipe (m)
m : friction constant of the delivery valve (m.s-1)
M1 : weight of the moving part of the waste valve (kg)
M2 : weight of the disc in the balloon (kg)
Mv : equivalent weight of the waste valve (valve +
spring) (kg), given by equation (6)
N : number of pushes between period 2 and period 3,
given by equation (32)
q : amount of pumped water per cycle (kg.s-1), given
by equation (57)
qs : amount of pumped water during the period 3
(kg.cycle-1), given by equation (34)
qsup: quantity of extra pumped water (kg.s-1), given by
equation (48)
Q : amount of lost water in a cycle (kg.s-1), given by
equation (56)
Q1 : amount of lost water during period 1 (kg.cycle-1),
given by equation (14)
Q6 : amount of water lost during the period 6 (kg.s-1),
given by equation (54)
r : radius of the supply pipe (m)
r2 : radius of the delivery pipe (m)
r3 : radius of the shrinked pipe (m)
rb : radius of the disc in the balloon (m)
rr: radius of the disc of the delivery valve (m)
rv : radius of the disk of the waste valve (m)
S0 : length of the waste valve stroke (m)
S1 : length of the delivery valve stroke (m)
S2 : length of the balloon membrane stoke (m)
ti : duration of the period i (i=1 to 6) (s)
tr : the duration of the last push at the end of the period
3 (s), given by equation (30)
T : duration of a complete cycle (s), given by equation
(55)
u : thickness of the supply pipe (m)
v0 : value of the water minimum velocity at which the
waste valve begins to close (m.s-1), given by
equation (3)
vf : velocity of the spring balloon membrane at the end
of period 3 (m.s-1), given by equation (46)
vi : water velocity in the supply pipe at the end of the
period i (i = 1 to 6) (m.s-1)
vr : velocity of the water in the supply pipe near the
end of period 3 (m.s-1), given by equation (31)
vB : water velocity at the outlet of the delivery pipe
(m.s-1), given by equation (47)
w : water density (kg.m-3)
Greek Letters
α6 : acceleration of the water column in the supply pipe
at the end of Period 6 or at the beginning of Period
1 (m.s-2), given by equation (10)
ζ : contraction coefficient (-), given by equation (40)
∆v: reduction in velocity (m.s-1), given by equation
(27)
θ: inclination angle of the pump from the horizontal
)
θ2 : solid angle in the shrinkage (°)
λ : linear head loss coefficient of the delivery pipe
during the pumping of the extra pumped water (-)
σ : Poisson’s ratio of the supply pipe material (-)
φ : coefficient of drag of the waste valve (-), given by
equation (2)
χ : angle at the enlargement (°)
ψ : factor related to the speed of the pressure-wave
transmission, given by equation (18)
REFERENCES
[1] W. M. Lansford and W. G. Dugan, An Analytical and
Experimental Study of the Hydraulic Ram. The University of
Illinois Urbana, 1941.
[2] Pump handbook, 3rd ed., I. J. Karassik, J. P. Messina, P.
Cooper, and C. C. Heald, McGraw-Hill, 2001.
[3] J. Pickford, Analysis of Surge, 1st ed., E. M. Wilson,
Macmillan and Co Ltd, 1969.
American Journal of Fluid Dynamics 2019, 9(1): 1-12 11
[4] A. H. Gibson, Hydraulics and its Applications. D. Van
Nostrand Company New York, 1908.
[5] International Development Research Centre, “Proceeding of a
Workshop on Hydraulic Ram Pump (Hydram) Technology”,
1985.
[6] T. D. Jeffery, T. H. Thomas, A. V. Smith, P. B. Glover, and
P.D. Fountain, Hydraulic Ram Pumps A Guide to Ram
Pump Water Supply Systems. ITDG Publishing, 1992.
[7] D. Jammes and T. Fouant, “Agriculture, Énergie &
Environnement Fiche technique 03 Bélier hydraulique.”
Inter-Réseau Agriculture Energie Environnement, p. 5, 2015.
[8] H. N. Najm, P. H. Azoury, and M. Piasecki, “Hydraulic Ram
Analysis: A New Look at an Old Problem,” Proc. Inst. Mech.
Eng., vol. 213, no. 2, pp. 127141, 1999.
[9] B. W. Young, “Simplified Analysis and Design of the
Hydraulic Ram Pump”, Proc. Inst. Mech. Eng., vol. 210, no. 4,
pp. 295303, 1996.
[10] J. Krol, “The Automatic Hydraulic Ram”, Proceedings of the
Institution of Mechanical Engineers, vol.165, no.1, pp. 5373,
1951.
[11] A. Pathak, A. Deo, S. Khune, S. Mehroliya, and M. M. Pawar,
“Design of Hydraulic Ram Pump,” Int. J. Innov. Res. Sci.
Technol., vol. 2, no. 10, pp. 290293, 2016.
[12] M. Inthachot, S. Saehaeng, J. F. J. Max, J. Müller, and W.
Spreer, “Hydraulic Ram Pumps for Irrigation in Northern
Thailand,” Agric. Agric. Sci. Procedia, vol. 5, pp. 107–114,
2015.
[13] A. Deo, A. Pathak, S. Khune, and M. Pawar, “Design
Methodology for Hydraulic Ram Pump,” Int. J. Innov. Res.
Sci. Eng. Technol., vol. 5, no. 4, pp. 47374745, 2016.
[14] Ansys CFD-Fluent R14.5, Engineering Simulation and 3D
Design Software. Ansys, Inc.: Canonsburg, Pennsylvania,
USA, 2014.
[15] D. F. Maratos, “Technical feasibility of wavepower for
seawater desalination using the hydro-ram (Hydram),”
Elsevier Sci. B.V., vol. 153, pp. 287293, 2002.
[16] P. Nambiar, A. Shetty, A. Thatte, S. Lonkar, and V. Jokhi,
“Hydraulic Ram Pump: Maximizing Efficiency,” 2015
International Conference on Technologies for Sustainable
Development (ICTSD), Mumbai, 2015, pp. 1-4.
[17] L. V Girish, P. Naik, H. S. B. Prakash, and M. R. S. Kumar,
“Design and Fabrication of a Water Lifting Device without
Electricity and Fuel,” Int. J. Emerg. Technol., vol. 7, no. 2, pp.
112116, 2016.
[18] S. Sheikh, C. C. Handa, and A. P. Ninawe, “A Generalised
Design Approach for Hydraulic Ram Pump: a Review,” Int. J.
Eng. Sci. Res., vol. 3, no. 10, pp. 551554, 2013.
[19] N. S. M. Hussin et al., “Design and Analysis of Hydraulic
Ram Water Pumping System,” J. Phys. Conf. Ser. 908
012052, 2017.
[20] ANSYS CFX R15.0, Engineering Simulation and 3D Design
Software. Ansys, Inc.: Canonsburg, Pennsylvania, USA,
2015.
[21] J. Krol, “A Critical Survey of the Existing Information
Relating to the Automatic Hydraulic Ram,” M.E (Technical
University of Warsaw), 1947.
[22] Rasetarivelo, “Pompe à Eau à Système de Ressorts Sans
Autre Source d’Energie que l’Eau”, 2004/012, 2004.
[23] S. Sheikh, C. C. Handa, and A. P. Ninawe, “Design
Methodology for Hydraulic Ram Pump (Hydram),” Int. J.
Mech. Eng. Rob. Res., vol. 2, no. 4, pp. 170175, 2013.
[24] Riadh Ben Hamouda, Notions De Mécanique des fluides
Cours et Exercices Corrigés Centre de Publication
Universitaire Tunis, 2008.
[25] B. Slim, “Chapitre IV : Dynamique des Fluides Réels
incompressibles”, in Support de cours Mécanique des
fluides, pp.3746, 2014. [Online]. Available:
https://www.technologuepro.com/cours-mecanique-des-fluid
es/chapitre-4-dynamique-des-fluides-reels-incompressibles.p
df.
[26] E. Abdelkader, Dynamique des Fluides Réels, 2016. [Online].
Available: https://www.researchgate.net/publication/
315619413_Dynamique_des_fluides_reels.
[27] B. W. Young, “Generic Design of Ram Pumps,” Proc Instn
Mech Engrs, vol. 212, no. 2, pp. 117124, 1998.
[28] J. Twyman, “Wave Speed Calculation for Water Hammer
Analysis” Obras y Proy., n. 20, pp. 86–92, 2016.
[29] S. Timoshenko and S. Woinowsky-Krieger, Thoery of Plates
and Shells, 2nd ed., McGraw-Hill Book Company, Inc., 1959.
[30] P. S. Gujar and K. B. Ladhane, “Bending Analysis of Simply
Supported and Clamped Circular Plate,” SSRG Int. J. Civ.
Eng., vol. 2, no. 5, pp. 17, 2015.
[31] R. Itterbeek, “ Chapitre 10. Compléments de Résistance des
Matériaux”, 2016. [Online]. Available:
https ://www.itterbeek.org/fr/index/cours-resistance-materiau
x.
[32] M. Pirotton and S. Erpicum, “UE Energie Hydroélectrique :
Ecoulements à Surface Libre et Sous-pression.”
[33] H. Guillon, “Hydraulique en Charge”, 2016. [Online].
Available : http://chamilo1.grenet.fr/ujf/main/document/
document.php?cidReq=LPROCSHEGE&id_session=0&gid
Req=0&origin=&id=498.
[34] A.-L. Zehour, “Hydraulique Générale”,2016.[Online].
Available: https://www.univ-sba.dz/ft/images/
hydraulique/Hydraulique_Générale.pdf.
[35] J. Vazquez, “Hydraulique Générale”, 2010. [Online].
Available: https://engees.unistra.fr/fileadmin/user_
upload/pdf/shu/COURS_hydraulique_generale_MEPA_201
0.pdf.
[36] M. Agelin-Chaab, “1.11 Fluid Mechanics Aspects of Energy”,
in Comprehensive Energy Systems, vol. 1, Elsevier Ltd., pp.
478520, 2018.
[37] D. Bach, F. Schmich, T. Masselter, and T. Speck, “A review
of Selected Pumping Systems in Nature and Engineering -
Potential Biomimetic Concepts for Improving Displacement
Pumps and Pulsation Damping,” Bioinspiration and
Biomimetics, vol. 10, no. 5, pp. 128, 2015.
[38] Matlab R2010a, High-performance Numerical Computation
and Visualization Software. The Mathworks, Inc.: Natick,
MA, USA, 2010.
12 Andriamahefasoa Rajaonison et al.: Theoretical Study of the
Behavior of a Hydraulic Ram Pump with Springs System
[39] H. Rakotondramiarana, T. Ranaivoarisoa, and D. Morau,
“Dynamic Simulation of the Green Roofs Impact on Building
Energy Performance, Case Study of Antananarivo,
Madagascar,” Buildings, vol. 5, no. 2, pp. 497520, 2015.
[40] H. Rakotondramiarana and A. Andriamamonjy, “Matlab
Automation Algorithm for Performing Global Sensitivity
Analysis of Complex System Models with a Derived FAST
Method,” J. Comput. Model, vol. 3, no. 3, pp. 17–56, 2013.
[41] B. W. Young, “Design of Hydraulic Ram Pump Systems,” J.
Power Energy, Proc. Inst. Mech. Eng. A, vol. 209, no. 4, pp.
313322, 1995.
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