MAPUA INSTITUTE OF TECHNOLOGY LAGUNA

__________________________________________________________
ME143L - MIT461 ACADEMIC YEAR 2024 - 2025

Laboratory Experiment # 3
Performance Evaluation of a Mini Turbine Pelton System

Group 5 Members:
Almonte, John Vincent D.
Amil, Sebastian Austin S.
Maneja, Leand Josh D.

DATE PERFORMED / SUBMITTED:

February 11, 2025 / February 18, 2025

INSTRUCTOR:
Engr. Manuel B. Rustria
Abstract

This laboratory report focuses on the performance evaluation of a mini Pelton turbine system.
The experiment aimed to simulate the operation of the Pelton turbine and record essential
parameters such as volume flow rate, pressure, speed, and net force. By analyzing these
parameters, we aimed to understand the operational characteristics of the turbine under
various load conditions. The study also involved plotting key performance curves, including
Torque vs. Speed, Power Output vs. Speed, and Efficiency vs. Speed. These curves are
critical in determining the turbine’s efficiency and its behavior during operation.

In addition to the data analysis, the experiment explored the racing characteristics of the
Pelton turbine to observe its performance at high speeds. Understanding these characteristics
is vital for determining safe operational limits and ensuring optimal efficiency during usage.
The turbine's ability to maintain power and efficiency at different speeds was carefully
studied, revealing key insights into its performance. Such evaluations are important for
small-scale power generation applications. The data provide a comprehensive understanding
of the turbine's potential in various operational settings.

A schematic diagram of the mini Pelton turbine system was drawn to illustrate its
components and layout. The main components include the water jet, buckets, and rotor,
which work together to convert hydraulic energy into mechanical energy. The description of
these components is essential for understanding the working principles of the Pelton turbine.
This report concludes that the mini Pelton turbine system demonstrates efficient energy
conversion, and the performance evaluation helps improve its design and application in
real-world scenarios.

Keywords: Pelton turbine, Performance evaluation, Volume flow rate, Pressure, Speed, Net
force, Torque vs. Speed, Power Output vs. Speed, Efficiency vs. Speed, Racing characteristics,
Schematic diagram, Energy conversion, Small-scale applications

2
Introduction

The Pelton turbine, an impulse type of hydraulic turbine, is widely used for high-head,
low-flow hydroelectric power generation. Its ability to efficiently convert hydraulic energy
into mechanical energy makes it an important component in both large-scale and small-scale
energy systems. The turbine operates by directing a high-velocity jet of water onto a series of
buckets mounted on a wheel, causing the wheel to rotate and generate mechanical power.
This design is particularly effective for locations with a high water head, where water is
directed from a significant height, maximizing energy potential.

In this experiment, a miniaturized version of the Pelton turbine was used to evaluate its
performance under controlled laboratory conditions. The primary objective of the experiment
was to simulate the turbine's operation and record essential performance parameters such as
volume flow rate, pressure, rotational speed, and net force. These measurements provided the
basis for analyzing key performance metrics, including torque, power output, and efficiency.
Plotting these values against speed allows for a detailed understanding of how the turbine
performs under varying conditions.

The results of this performance evaluation contribute to a broader understanding of how mini
Pelton turbines can be applied in small-scale hydroelectric systems. By understanding the
racing characteristics and efficiency across different speeds, the experiment helps inform
future design and optimization of such systems. The insights gained are especially relevant in
developing regions and remote areas where small-scale energy solutions can be employed to
harness renewable energy sources efficiently.

3
Working Principle
The Pelton turbine operates on the principle of converting the kinetic energy of water into
mechanical energy through impulse action. Water, typically under high pressure from a
reservoir or penstock, is directed into one or more nozzles, which accelerate it into
high-velocity jets. These jets strike the turbine's spoon-shaped buckets (also known as
blades), which are mounted around the circumference of a wheel. The shape of the buckets
splits the incoming water jet into two streams, ensuring the force is distributed evenly across
the surface of the bucket.

As the water jet strikes the buckets, it imparts momentum, causing the turbine wheel (runner)
to rotate. The key to the turbine's efficiency is that the water exits the bucket at nearly zero
velocity, ensuring that most of its kinetic energy is transferred to the rotating wheel. The
mechanical energy generated from the rotation of the turbine wheel can then be used to drive
an electrical generator or perform other mechanical tasks.

One of the advantages of the Pelton turbine is that it is an impulse turbine, meaning it
operates in air, and only the water jets and buckets are involved in energy conversion, making
it well-suited for high-head, low-flow conditions. The rotational speed of the turbine depends
on factors such as the water flow rate, pressure, and the number of nozzles directing water to
the turbine. By adjusting these variables, the output and efficiency of the Pelton turbine can
be optimized.

4
Objectives
General Objectives: to evaluate the Pelton turbine characteristics under various flow rates
and heads.

Specific Objectives:
1.​ To simulate the operation of a Pelton turbine.
2.​ To record the volume flow rate, pressure, speed, and net force.
3.​ To plot the Torque vs. Speed curve, Power Output vs. Speed curve, and the Efficiency
vs. Speed curve.
4.​ To determine the racing characteristics of a Pelton turbine.
5.​ To draw the schematic diagram of a Pelton turbine system and describe its
components

Methodology
●​ Equipment, Tools, and Materials
a.​ Equipment
-​ HT 201 Mini Pelton Turbine Test Set

b.​ Tools and Materials

-​ Tachometer

-​ Thermometer

5
 -​ Extension cord

-​ Digital Clamp

●​ Safety Procedures
-​ Follow instructions and only work on authorized tasks.
-​ Keep the workplace clean and orderly.
-​ No horseplaying inside the laboratory room.

●​ Testing Procedures
○​ Before the Experiment

-​ Pay attention to the instructions in lectures.

-​ Borrow necessary tools, materials, and equipment.
-​ Prepare the workplace for the experiment.

○​ During the Experiment

-​ Attach the clamp meter to the pump's live wire.
-​ Loosen the bolt connected to the turbine wheel until there is no
contact.
-​ Open the discharge valve of the pump fully.
-​ Record the temperature of the water, and measure the diameter radius
of the flywheel.

6
-​ Turn on the pump.
-​ Turn the knob for the pressure to the maximum setting, then observe
what happens in the turbine.
-​ Adjust the knob for the pressure to the desired valve.

-​ Tighten the belt to apply load to the wheel of the turbine.

-​ Record the initial and final measurement of the nutating disc meter for
10 seconds.

7
 -​ Measure the speed of the wheel of the turbine using a tachometer.

-​ Record the current flowing, through the live where to the pump.

-​ Record the net force applied to the wheel, and make sure that the
pressure is maintained to the desired valve.
-​ Repeat steps 8 to 12 five times with varying forces applied to the
wheel.
-​ Adjust the knob for the pressure again to the desired value.
-​ Repeat steps 8 to 12 five times, again with varying turbine applied to
the wheel.
-​ Record the final temperature of the fluid
-​ Turn off the pump.

○​ After the Experiment

-​ Clean the workplace.
-​ Return the materials, tools, and equipment.
-​ Compute the torque, power and efficiency of the turbine system.
-​ Create the initial report of the experiment.

8
 Table and Results

Initial Water Temperature: 50 C​ ​ Final Water Temperature: 51 C

Pulley Radius: 37.5 mm

Trial Volume Net Load Pressure Time Current Voltage Speed

Number (m^3) (N) (kg/cm^2) (s) (A) (V) (rpm)
Initial Final
1 20.42 20.44 7 1.1 10 5.1 220 2186

2 20.55 20.57 10 1.1 10 5.1 220 2154

3 20.76 20.78 12 1.1 10 5.1 220 1949

4 20.82 20.84 14 1.1 10 5.1 220 1936

5 20.88 20.9 15 1.1 10 5.1 220 1943

6 22.25 22.29 8 1.3 10 4.2 220 2298

7 22.34 22.38 11 1.3 10 4.2 220 2172

8 22.38 22.42 13 1.3 10 4.2 220 2045

9 22.48 22.52 15 1.3 10 4.2 220 1944

10 22.53 22.57 16 1.3 10 4.2 220 1754

Table 1.1. Data Collected

Trial Net Load Flow Torque 𝑃𝑖𝑛 WP BP η𝑜𝑎1 η𝑜𝑎2

Number (N) Rate(m^3/s) (N-m) (W) (W) (W) (%) (%)

1 7 0.002 0.2625 1122 215.82 59.51 27.57 5.3

2 10 0.002 0.375 1122 215.82 84.59 39.19 7.54

3 12 0.002 0.45 1122 215.82 91.84 42.55 8.19

4 14 0.002 0.525 1122 215.82 106.44 49.32 9.49

5 15 0.002 0.5625 1122 215.82 114.45 53.03 10.2

6 8 0.004 0.3 924 431.64 72.19 16.72 7.81

7 11 0.004 0.4125 924 431.64 93.82 21.74 10.15

8 13 0.004 0.4875 924 431.64 110.88 25.69 12

9
9 15 0.004 0.5625 924 431.64 120.46 27.91 13.04

10 16 0.004 0.6 924 431.64 110.21 25.53 11.93

Table 1.2. Computational Data

Calculations

1.)​ Net Volume, ∆𝑉

3
​ ∆𝑉 = 𝑉𝑓𝑖𝑛𝑎𝑙 − 𝑉𝑖𝑛𝑖𝑡𝑎𝑙 = 20. 44 − 20. 42 = 0. 02 𝑚

2.)​ Torque, T

1𝑚
𝑇 = 𝐹𝑛𝑒𝑡 + 𝑟𝑝𝑢𝑙𝑙𝑒𝑦 = (7 𝑁 × (37. 5 𝑚𝑚 × 1000𝑚𝑚
)) = 0. 26 𝑁 − 𝑚

3.)​ Volume Flow Rate, Q

2 3
∆𝑉 0.02 𝑚 𝑚
𝑄= 𝑡
= 10 𝑠
= 0. 002 𝑠

4.)​ Water Power, WP

2 3
𝑘𝑔 9,81 𝑁 10 𝑐𝑚 𝑚 1𝑊
𝑊𝑃1 = 𝑃𝑄 = [(1. 1 2 )( 1 𝑘𝑔𝑓
)( 2 )][0. 002 𝑠
] × 𝑚 = 215. 81 𝑊
𝑐𝑚 1𝑚 1 𝑁• 𝑠

5.)​ Brake Power, BP

2186 𝑟𝑝𝑚
𝐵𝑃 = 2π𝑁𝑇 = 2π ( 60
)(0. 26) = 59. 51 𝑊

6.)​ Overall Efficiency (In terms of Brake Power), %

𝐵𝑃 59.51 𝑊
η𝑜𝑎1 = 𝑊𝑃
= 215.82 𝑊
= 27. 577%

7.)​ Power Input, Pin

𝑃𝑖𝑛 = 𝑉𝐼(𝑃𝐹) = (220 𝑉)(5. 1 𝐴)(1) = 1122 𝑊

8.)​ Overall Efficiency (In terms of Pin), %

𝐵𝑃 59.51 𝑊
η𝑜𝑎2 = 𝑃𝑖𝑛
= 1122 𝑊
× 100 = 5.3 %

10
Graphs

Graph 1.1

Graph 1.2

Graph 1.3

11
Graph 1.4

Graph 1.5

Graph 1.6

12
Parts and Functions

1.​ Reservoir – Stores the supply water used in the system.

2.​ Pump – A machine used to transport fluid in the system.

3.​ Pump Switch – Used to turn on and off the pump.

4.​ Nutating Disk Flow Meter – Measures the volume of water flowing in the system.

5.​ Pressure Gauge – Measures the pressure of the fluid in the system.

6.​ Spring Balance – Used to measure the net force applied to the wheel.

7.​ Pelton Wheel Turbine – Extracts energy from the impulse of moving water.

8.​ Nozzle – Controls the jet of the liquid.

13
Discussion

The performance evaluation of the mini Pelton turbine system reveals key insights into its
efficiency, power output, and operational stability. The experimental results indicate that the
efficiency of the system is directly influenced by parameters such as nozzle diameter, water
flow rate, and rotational speed of the runner. It was observed that optimizing the nozzle size
and maintaining a stable water head significantly improved the turbine's performance,
yielding a higher mechanical efficiency. However, deviations from optimal conditions, such
as fluctuations in water supply or misalignment of the nozzle, led to efficiency losses and
mechanical wear over time.

Another crucial finding is the relationship between the turbine’s rotational speed and the
applied load. At lower loads, the turbine demonstrated high rotational speeds, but excessive
loading led to a reduction in power output due to increased resistance. This suggests that the
system operates best within a specific range of loads to maintain efficiency. Furthermore,
performance losses were observed due to frictional losses in the bearings and mechanical
components, which highlights the need for regular maintenance and lubrication to sustain
long-term operation.

The study also emphasizes the sustainability of using a mini Pelton turbine for small-scale
energy generation. Given its simple design and the ability to operate with relatively low water
heads, this system presents a viable solution for off-grid electricity generation, especially in
rural areas. However, further research is recommended to explore material durability,
long-term efficiency trends, and integration with energy storage systems to enhance its
reliability.

14
Conclusion

The performance evaluation of the mini Pelton turbine system demonstrates its potential as an
efficient and sustainable source of hydroelectric power for small-scale applications. The
findings confirm that optimizing key parameters such as water flow rate, nozzle size, and
applied load significantly improves the efficiency and power output of the system. Proper
alignment and regular maintenance are essential to minimizing mechanical losses and
ensuring long-term operational stability.

Despite its advantages, the system does have limitations, including efficiency losses due to
mechanical friction and dependency on a consistent water supply. Addressing these
challenges through improved materials, lubrication techniques, and automation could further
enhance performance. Additionally, incorporating real-time monitoring systems using IoT
technology may help in optimizing its operation and preventing potential failures.

Overall, the mini Pelton turbine system presents a promising solution for decentralized
renewable energy generation, particularly in remote locations with access to small water
streams. Future studies should focus on expanding the design for larger applications and
integrating smart control mechanisms to maximize efficiency and sustainability. The
continued development of such micro-hydro systems can contribute significantly to the
transition toward clean and renewable energy solutions.

15
Supplementary Information

Additional experimental data, including raw performance measurements, efficiency

calculations, and variations under different load conditions, are provided in the
supplementary section for further validation of the findings. The data sets include turbine
speed versus power output graphs, nozzle optimization charts, and head-efficiency
relationship tables, which offer a comprehensive analysis of system performance. These
supplementary materials are essential for researchers seeking to replicate the study or
improve upon its methodology.

Moreover, detailed schematics and engineering drawings of the mini Pelton turbine setup,
including its nozzle arrangement, runner specifications, and support structures, are included
to provide a better understanding of the system’s design. A breakdown of the materials used,
the fabrication process, and potential modifications for improving durability and efficiency is
also discussed. These insights can help engineers and researchers in designing more robust
and adaptable micro-hydro systems.

In addition, a section on computational modeling and simulations of the turbine system is

presented, which compares theoretical predictions with experimental results. This
supplementary information highlights the discrepancies between ideal and real-world
conditions, helping to refine performance estimation models. By integrating these findings
with practical implementation, future designs can be optimized for higher efficiency and
reliability in real-world applications.

16
References

Miller, R. W. (1996). Flow Measurement Engineering Handbook (3rd ed.). McGraw-Hill.

Moran, M. J., Shapiro, H. N., Boettner, D. D., & Bailey, M. B. (2018). Fundamentals of
Engineering Thermodynamics (9th ed.). Wiley.

White, F. M. (2021). Fluid Mechanics (9th ed.). McGraw-Hill.

17