Presented in World Hydro Conference 2012 in New Delhi The detail working is avialable in video http://www.youtube.com/watch?v=kcf5bGglRXg The theoretical description in http://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=2&cad=rja&ved=0CDIQFjAB&url=http%3A%2F%2Fwww.tjprc.org%2Fdownload.php%3Ffname%3D2-11-1361528273-3.Civil%2520-IJCSEIERD%2520-%2520Introduction%2520to%2520-full.pdf&ei=yTxtUpLIB46BrgeU2YHQDA&usg=AFQjCNFgLuyDjYUsptplm157MorW9oOinw&sig2=UbmAqRiAPDFJ6NZt2MBBeg&bvm=bv.55123115,d.bmk

1. A NOVEL METHOD OF GENERATING
HYDROELECTRIC POWER USING A
LARGE COLLAPSIBLE BLADDER
Dr Uday Prashant

2. BASIC CONCEPTS
My discovery involves two basic concepts
1) Flow induced collapse in collapsible
tubes
2) Fluid structure interactions in flexible
tubes
This combinations leads to development of
novel hydroelctric turbine which functions at
very low heads and low flow conditions
efficiently

3. • With conventional turbine technology it is
practically impossible to extract power from
such low energy density flows –
head 1 -2 m range,
flow rate 0.3 – 0.4 litre/ sec
velocity 1 -3 m/sec.
Power in 1- 4 w & efficiency 60 – 95 %
Actually even lower flow conditions it is
possible to generate power with this method
but I lacked proper instrumentation to do so

5. • High head: 100-m and above- Pelton wheel require low
flow rates; 10 -30 cubic m/sec
• Medium head: 30 - 100 m; Francis require moderate
flow rates 30 -70 cubic m/sec
• Low head: 2 - 30 m; requires large flow rates. 50 – 100
cubic m/sec
• For Pico power project :- A 1 kW scheme could acquire
its energy from 200 m head with a flow rate of 1 litre/sec
or 2 m head with a flow rate of 100 l/sec
. With current technology either of them must be
large i.e high energy density flows are required for
operation conventional turbines efficiently

7. Basic principle of all turbines
• The power extraction from fluid arises from
turning the flow of jets.
• The fixed blades are stators and rotating
blades are rotors.
• The change in momentum of jets
causes reaction on rotatory blades and
transfers energy to shaft.

8. V= Absolute velocity of fluid
Vr= Relative velocity of fluid
Vw= Whirl velocity
Va= Axial velocity of flow
u = Velocity of the moving blades
m = V A (Area of blades)

9. In low energy density flows in
hydrokinetic turbines are but
they are inefficient and
dependant upon velocity of
water which is limited under
natural conditions
What if we have turbine which will
do away with these jets & vanes
or blades and operates by
entirely different mechanism
then we can produce energy at
even at low flow and head
conditions which was previously
not possible.

10. Specific Speeds

11. • More specific speed – lower efficiency and
increases cost
• Large heads---- large reserviors/dams–
submerge large areas of lands--- possible only in
mountain areas which act as natural reserviors,
• Large flows--- disturb entire course of river flow------ very costly ---lot of civil work required--- long
term can cause earthquakes

13. Ultra Low Head Turbines

14. Zero Head floating Hydrokinetic devices
work like wind mill – low efficiency

15. Novel turbine –Novel principle
• The flow is instantaneously reduced. Steady
continuous flow is converted to unsteady
pulsatile flow by collapsible bladder
• There is large negative pressure “WAVE”
generated travelling at speed of sound in
water.
• This pressure wave interacts with specially
designed flexible tubes with elastic supports and
transmits energy.

17. Advantages
• It works at very low Heads 1 – 2 m
• It works at very low flows also – viable even at such
low flows 250 ml/sec
• It works in lower velocities 1 -3 m/sec of flow
• It is very cost effective/ economically viable
. No concept of specific speed, works in wide flow
conditions

18. Advantages
• It can be used in small streams also.
• Doesn’t require complex civil engineering work
• Can be installed in few days of time.
• It is environmentally friendly (fish friendly)
• It is mobile and can also be easily shifted and installed in
other locations with similar flow conditions

22. Schematic diagram of novel
pulsatile flow generator

24. Working Principle
• Bladder collapses because of Venturi effect, or application of
Bernoulis Principle
• FSI or waterhammer effect causes the cycle to repeat and
converts kinetic energy of water to pressure wave which is inturn
converted to motion of pipes

25. Formulae
• From Joukowsky equation”
dp = d * c * dv
dp is pressure surge developed during the water hammer
c is velocity of sound in water
dv is change in velocity which is same as
V = (2gH)1/2 as after collapse velocity is zero & H is height of baldder from
.
ground

26. • The pressure energy acts on entire surface of the u and straight
tube and ther force acting on it is given by
• F=P*A
• A = 2* pi * r2 + 2*pi*H
• If f is the frequency; s is amplitude of ocillations then power
generated per second is proportion to P * A * f * s
•

27. Vertical Height fixed at 1.8 m from bladder to lower end of
distal straight tube of diameter 12 mm. Spring constant
38 kg/m
Volume of flow in
l/sec
Frequency
no/min
Force in Kg
Amplitue in cm Newton
Power
avialable
Power in watts
Hydraulic efficiency
%
0.18.
136
3
1 kg
3.1w
0.76w
24
0.2
128
8.5
1.085
3.6w
1.2w
35
0.222
114
9
1.125
3.9w
1.8w
45
0.227
115
8
1.150
4w
3w
75
0.25
112
10.
12.
4.4w
3.9w
89
0.3
106
10.5
12.50
5.3w
4.77w
90

28. When Flow rate is fixed at 250 ml/sec and height is varied the power
and efficiency.
Vertical height
in cm
Freq of oscill
per min
Amplitude
In mm
Max Force
Per
Oscillation in
Kg
Power available in
watts
Power generated
watts
30
96
1
0.1
0.1w
0.03w
0.42781
50
92
30
0.5
0.49w
0.32w
35
96
91
54
0.7
0.7w
0.41w
47
130
86
70
1
0.98w
0.67w
63.7
150
97
76
1.12
1.1w
0,8w
80
165
58
85
1.25
1.3w
1.0w
64
Hydraulic
efficiency

29. Frequency and amplitude of oscillations
140
120
100
80
60
Frequency of oscillations per min
Amplitude of vibrations in mm
40
20
0
Flow rate in ml/sec

30. Variation of frequency with height at constant flow rate of
240 cm^3/sec
frequency and amplitude of oscillations
frequency of oscillatons
Amplitude of oscillations
120
100
80
60
40
20
0
30
50
96
Vertical height in cm
130
150
165

31. Hydraulic efficiency % as flow rate is increased
and when height is fixed 180cm
100
90
80
70
60
50
40
30
20
Hydraulic efficiency %
10
0
0.18.
0.2
0.222
0.227
0.25
0.3

32. When the area of tube is increased from 12 mm to 18 mm and thickness of
rubber balloon is doubled (1.5 mm) and rest of parameters held constant
following observations are noted. Height =1.5m
Vol of water
Flow in cc/sec
Freq of oscill per
min
Amplitude
In mm
Power available from
flow in watts
Power generated in watts
Hydraulic efficiency in
%
0.18
136
45
2.6w
1.7w
65
0.2
128
55
3w
2.4w
80
0.22
114
65
3.2w
2.9w
92
0.23
115
55
3.3w
2.16w
65
0.25
112
70
3.6w
3.42w
93
0.3
106
80
4.4w
4.2w
95
0.33
100
85
4.9w
4.48w
92
But increasing further flow caused rupture of bladder due to the stresses and hence
my further experiments fur stopper at larger diameter than ¾ inch pipes

33. Hydraulic Efficiency of apparatus at various flow rates in liter/sec when other paramerters are
constant
100
90
80
70
60
50
40
30
20
10
0
0.18
0.2
0.22
0.23
0.25
0.3
0.33

37. STEADY FLOW: CHOKING, FLOW LIMITATION AND ELASTIC
JUMPS

38. Pressure recorded distal to collapsible bladder when all conditions constant
Time in sec
0
-20
-40
Pressure in mm Hg -ve
-60
-80
-100
-120
-140
-160
-180
-200

39. Theory of Waterhammer
• The bladder once collapsed must remain in
same state under ordinary conditions.
• But due to flexible ‘U’ tube with elastic
supports it comes out of collapse state and
extracts energy by water hammer effect.
• Water hammer effect is when velocity of flow
changes too rapidly (t< 4L/C where L is
length of tube and C is velocity of sound in
water (1200m/sec))

40. Types of Coupling
• The most significant mechanism is the
junction coupling, others are
Poisson and
friction coupling
• Wiggert D.C, Tijsseling, A. S (2001)- Junction coupling is
taken place due to unsupported discrete points of the
piping systems such as unrestrained
valves, junctions, closed ends, pumps, etc.
• MOC (Method of Charecteristics) and FEM (Finite
Element Method) are used to solve structural equations.

41. A.S. Tijsseling; A.G.T.J. Heinsbroek; THE INFLUENCE OF BEND MOTION ON WATERHAMMER
PRESSURES AND PIPE STRESSESProceedings of the 3rd ASME/JSME Joint Fluids Engineering
Conference July 18-23, 1999, San Francisco, California

44. A hydraulic ram or impulse pump is a device which uses the energy of
falling water to lift a lesser amount of water to a higher elevation than the
source but never used for power generation.

47. Conclusions
• Novel technological innovations may solve some of basic
limitations inherent in current hydro electric turbine
designs
• My model is in pilot stages and needs considerable
refinement and in large scale has to be rigorously tested.
•
Lastly if similar technological principles were used in
design of gas turbine then results may be more
significant and have far reaching impact

48. When something is new, they say
"it's not true".
When its truth becomes
obvious, they say "it's not
important".
When its importance cannot be
denied, they reason, "it's not new".
William James

49. Thank You