Detailed Design of Kaplan Turbine for Australian Hydropower Use

This report presents a detailed design of a Kaplan turbine for hydropower generation, specifically focusing on applications within Australia. It begins with an introduction to hydropower as a sustainable energy source and the suitability of Kaplan turbines for low-head sites. The report includes a literature review of Kaplan turbine development and operation, followed by a methodology section that outlines the working principle, schematic diagrams, and relevant formulas for power calculation, specific speed, and runner speed. A mathematical model for blade distortion, velocity triangles, and blade thickness is presented. The report concludes with results, discussion, and recommendations for effective Kaplan turbine design, emphasizing its potential for contributing to renewable energy solutions in Australia. Desklib provides access to this report, along with a wealth of study resources including past papers and solved assignments.

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DESIGN OF KAPLAN TURBINE
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Executive Summary
The usage of a cheap, clean source of electrical energy has been a big achievement for
most parts of the world including Australia for the last few years, especially the hydroelectric
power since flowing water is free. Basically, electricity is produced from hydropower energy that
is made available due to the potential energy created from the pressure head, hydro sites as well
as water discharge. Grounded on the location of the hydropower several types of hydro turbines
can be developed and designed depending on the requirements of the designers and developers to
produce electric energy. The key concern is to lower the rate of the dependency on the fossil
fuels which are very harmful to our environment and boost the use of cheap and renewable
sources of electrical energy in most parts of Australia both the towns and the rural. In this paper,
we will design a reaction turbine (Francis/Kaplan) for hydro-power generation in Australia.

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Table of Contents
Executive Summary.....................................................................................................................................2
CHAPTER 1: Introduction..........................................................................................................................3
1.1 Background.......................................................................................................................................3
1.2 Scope.................................................................................................................................................4
1.3 Objectives..........................................................................................................................................5
CHAPTER 2: Literature Review.................................................................................................................6
CHAPTER 3: Methodology...........................................................................................................................8
3.1: Working Principle.............................................................................................................................8
3.2 Schematic diagram......................................................................................................................9
3.3 Formula Or Theory.....................................................................................................................10
3.3.1 Power.................................................................................................................................10
3.3.2 Specific Speed....................................................................................................................11
3.3.3: Speed of the Runner (N)..........................................................................................................11
3.4 Required mathematical model and design......................................................................................12
3.4.1 Distortion of the Blade..............................................................................................................12
3.4.2: Velocity Triangle......................................................................................................................13
3.4.3 Thickness of Blade Section........................................................................................................15
CHAPTER 4: Result.....................................................................................................................................18
CHAPTER 5: Discussion..............................................................................................................................20
CHAPTER 6: Conclusion and recommendation..........................................................................................21
CHAPTER 7: References.............................................................................................................................23
Appendices................................................................................................................................................24

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Table of tables
Table 1: Showing Classification of Turbines...............................................................................................5
Table 2: Showing the budget for development.........................................................................................18
Table 3: Result Data of Blade Profile.........................................................................................................19
Table 4 Result Data of Forces acting on Blade...........................................................................................20
Table 5: Result Data of Blade Thickness....................................................................................................21
Table of Figures
Figure 1: Showing Basic Layout of a Kaplan Turbine ................................................................................6
Figure 2: general arrangement of a typical Kaplan Turbine ........................................................................8
Figure 3: shows Kaplan Turbine having a different number of blades as 3, 4, and 5 ..................................9
Figure 4: showing the working principle of the Kaplan Turbine ...............................................................10
Figure 5: Showing Schematic diagram 1....................................................................................................10
Figure 6: Showing Schematic diagram 2 ...................................................................................................11
Figure 7: Showing Schematic diagram 3 ...................................................................................................12
Figure 8: Showing Blade section ...............................................................................................................14
Figure 9: Velocity Triangle of Kaplan Blade...............................................................................................16
Figure 10: Showing Blade Section..............................................................................................................17
Figure 11: Showing the Gantt Chart...........................................................................................................19

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CHAPTER 1: Introduction
1.1 Background
Hydropower produced basically from hydroelectric rivers falls and dams are very
sustainable, clear and green sources of electrical energy which generates relatively cheaper
electricity and also reduces the emission of carbon (Hall, 2010). Due to the source`s high energy
density, hydropower is one of the most effective and highly primary available green power
sources that generate electrical energy. For it to have higher efficiency, there must be
installations of the hydraulic turbines in the power plant which are very suitable based on the
head and site discharge (Krivčenko, 2014). There are several hydraulic turbines which can be
employed and these two common types include;
1. Reaction Turbines
2. Impulse Turbines
An impulse turbine is that hydraulic turbine in which all the energy (hydraulic) obtained from
water are converted to the kinetic energy before the water arrived at the turbine runner. While in
the reaction turbine there is some hydraulic energy available which are converted to kinetic
energy before the water strikes the turbine`s runner. The reaction turbine is well suited due to the
head range present at any chosen construction site. There are three well-known reaction turbines
which are ;
1. Pelton
2. Francis
3. Kaplan

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Table 1: Showing Classification of Turbines
Number Type Head Flow rate Specific Speed
1 Kaplan Turbine Low High High
2 Pelton Turbine High Low Low
3 Francis medium Medium Medium
1.2 Scope
In this paper we will make the design on the Kaplan turbine, these turbines have
relatively high specific speed, smaller dimension, therefore, the dimension of the generator are
somehow smaller that always result into the relatively lower cost (Krishna, 2017). Moreover, the
Kaplan turbine has an overload capacity, Water moves via Scroll housing directly into the guide
vane in the radial direction. From this point, it flows making a right angle and then enters the
runner axially. There are as well types of the Kaplan Turbines, that is double and single
regulated, the first one contains just adjustable runner blade while the latter contains both
flexible and adjustable guide vane (Nechleba, 2011). Basically, Kaplan turbine is operational for
a head range of about 2m and 40 m. The double regulated Kaplan operates in a large range of the
designed discharge which is always in 15% - 100 %, but single regulated turbine work at a very
lower range of 30%-100%. The diagram below shows a Kaplan turbine;

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Figure 1: Showing Basic Layout of a Kaplan Turbine (Fielding, 2011).
In this design, we will focus on the low head Kaplan turbine runner since the low head
schemes can be readily executed runoff- rivers and canals. The key focus is on the development
and design of the Kaplan turbine blade for hydro-power generation in Australia. The key features
based on the site will also be calculated during the design.
1.3 Objectives
 To develop a complete case study on hydropower plant (where using reaction turbine)
located anywhere in the world.
 To study the prospect of hydro energy in Australia and identify at least two potential
sites suitable for reaction turbine applications.
 To design (i.e. blade, guide vane, stationary vanes, runner, casing etc.) for an effective
reaction turbine for the selected site.

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 To analyse performance characteristics (i.e. power output, torque, in-out velocity profile,
flow rate, losses, cavitation etc.) of the designated turbine.
CHAPTER 2: Literature Review
The first effort to use the adjustable blades was done in the year 1867 by a scientist by the
name Ludlow O.W who issued the patent of the clue of the design. But now the person who
really made attempts are finally succeeded to develop the Kaplan Turbine was Victor Kaplan
was an Australian engineer. This was done during the early twentieth century actually to be
specific it was Thursday 23rd August 1934 (patent in the public domain, that day the design was
successful). This type of turbine is actually an improvement through modifications from the
Francis Turbine, this was done through the addition of adjustable runner blades. Kaplan is
always installed in large rivers as well as Dams (Zhang, 2010).
The head experienced from this type of Turbine ranges from 1.5 meters to about 50. This
type of Turbine always works best at between heads of 1.5 meters and 15meters. But at a head
over 15, the efficiency of the Kaplan turbine will begin to reduce. This type of turbine can be
vertically or horizontally oriented depending on the flow input. The Kaplan Turbine which are
vertically oriented permits for runner diameter for about 10 meters (Singal, 2012). It is also
possible to increase the efficacy of the Kaplan turbine through adjusting the inlet angle, the
turbine radius, blade pitch angle as well as the exit angle. All these factors are very exceptional
due to the rate of flow for every particular site as well as the scenario of the flow. This type of
the turbine`s efficacy is actually suitable in almost every part of the world since it does not need
much head (Taylor, 2014). The below is a general arrangement of typical Kaplan Turbine;

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Figure 2: general arrangement of a typical Kaplan Turbine (Coutu, 2012).
Bigger Kaplan turbine contains relatively bigger potential energy which generates sufficient
hydroelectric power to help power up to about five million households a year in Australia. And this is
equal to about twenty million oil barrels which are almost about 10 million metric tons of carbon (iv)
oxide emission. Together with the Kaplan variable head, it can generate and also produce an output
which ranges from small KW to about 230 Megawatts. The diagram below shows Kaplan Turbine having
a different number of blades as 3, 4, and 5.
Figure 3: shows Kaplan Turbine having a different number of blades as 3, 4, and 5 (Nechleba, 2011).

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CHAPTER 3: Methodology
3.1: Working Principle
The Kaplan Turbine operates as follows, water from the penstock enters the casing scroll, the
casing is constructed in the suitable shape which ensures that the pressure is maintained during the
operation. The water is then directed into the runner blades through the guide vanes (Coutu, 2012). The
vanes are made to be flexible and it is possible to adjust itself in accordance with the specification of
flow rate. Water makes a turn of 90 degrees, thus the direction of the water is axial to runner blades.
The Kaplan blades then start to revolve as water hits due to the reaction force of the moving water
( hence the name reaction turbine).
The blades contain twist along its length so as maintain an optimum angle of attack for all cross-
section of blades to realize greater efficacy. Water then enter into the draft tube from runner blade
immediately, here the pressure of water energy and kinetic energy will reduce. Kinetic energy will be
converted into pressure energy and this results to pressure increase of the water. Therefore the
rotation of the turbine is employed to rotate the shaft to help produce electrical energy. The diagram
below shows the working principle of the Kaplan Turbine
Figure 4: showing the working principle of the Kaplan Turbine (Fielding, 2011).

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3.2 Schematic diagram
Figure 5: Showing Schematic diagram 1 (Nechleba, 2011).
Figure 6: Showing Schematic diagram 2 (Nechleba, 2011).

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Figure 7: Showing Schematic diagram 3 (Nechleba, 2011).
3.3 Formula Or Theory
Some of the basic formulae employed in Kaplan Turbine are illustrated as below;
3.3.1 Power