Based on the given information:
ω = 6 rev/s = 360 rpm
Q = 10 ft3/s
hT = 20 ft
Wshaft = ρgQhT = 62.4hp
Calculating the specific speed:
N's =
ω(rpm)√Wshaft(bhp)
(hT(ft))5/4
=
360√62.4
205/4
= 580
From the specific speed chart, a turbine with a specific speed of 580
would be a Francis turbine, which is suited for mixed or radial flow.
Therefore, a Francis turbine should be selected for this
Here you find all about Kaplan Turbine. You will also able to know how its work, main parts of it, design factors, equations, application, capacity, efficiency, advantages-disadvantages and etc. I think it will very much helpful for you. If you find any problem please do inform for correction. Thank you.
Hydraulic Turbines-Classification,Impulse and Reaction Turbine, Layout of Hyd...Mechanicalstudents.com
Hydraulic turbines are machines which convert hydraulic energy into mechanical energy. If the machine transforms mechanical energy into hydraulic energy it is called a pump. Thus in turbines, fluid does work on the machine and machine produces power. but, the pump absorbs the power and work is done on the fluid.
For more information, visit https://mechanicalstudents.com/hydraulic-turbines-classification-impulse-and-reaction-turbine-layout-of-hydroelectric-power-plant/
A steam turbine is a prime mover in which the potential energy of the steam is transformed into kinetic energy and later in its turn is transformed into the mechanical energy of rotation of the turbine shaft
Watch Video of this presentation on Link: https://youtu.be/OFIgUfclEHU
For notes/articles, Visit my blog (link is given below).
For Video, Visit our YouTube Channel (link is given below).
Any Suggestions/doubts/reactions, please leave in the comment box.
Follow Us on
YouTube: https://www.youtube.com/channel/UCVPftVoKZoIxVH_gh09bMkw/
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A turbine (from the Latin turbo, a vortex, related to the Greek is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating electrical power when combined with a generator A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Early turbine examples are windmills and waterwheels.
Here you find all about Kaplan Turbine. You will also able to know how its work, main parts of it, design factors, equations, application, capacity, efficiency, advantages-disadvantages and etc. I think it will very much helpful for you. If you find any problem please do inform for correction. Thank you.
Hydraulic Turbines-Classification,Impulse and Reaction Turbine, Layout of Hyd...Mechanicalstudents.com
Hydraulic turbines are machines which convert hydraulic energy into mechanical energy. If the machine transforms mechanical energy into hydraulic energy it is called a pump. Thus in turbines, fluid does work on the machine and machine produces power. but, the pump absorbs the power and work is done on the fluid.
For more information, visit https://mechanicalstudents.com/hydraulic-turbines-classification-impulse-and-reaction-turbine-layout-of-hydroelectric-power-plant/
A steam turbine is a prime mover in which the potential energy of the steam is transformed into kinetic energy and later in its turn is transformed into the mechanical energy of rotation of the turbine shaft
Watch Video of this presentation on Link: https://youtu.be/OFIgUfclEHU
For notes/articles, Visit my blog (link is given below).
For Video, Visit our YouTube Channel (link is given below).
Any Suggestions/doubts/reactions, please leave in the comment box.
Follow Us on
YouTube: https://www.youtube.com/channel/UCVPftVoKZoIxVH_gh09bMkw/
Blog: https://e-gyaankosh.blogspot.com/
Facebook: https://www.facebook.com/egyaankosh/
A turbine (from the Latin turbo, a vortex, related to the Greek is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating electrical power when combined with a generator A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Early turbine examples are windmills and waterwheels.
This Presentation is about working principle of Pumps.Basic Presentation regarding pumps , will definitely help beginners to learn pump types , their working , their parts etc.
This presentation will educate you with the basics and types of a turbine . For info on any topics related to mechanical , feel free to inbox me . I'm available at vijayvicky.vicky7@gmail.com
Design, Modeling & Analysis of Pelton Wheel Turbine BladeIJSRD
A Pelton-wheel impulse turbine is a hydro mechanical energy conversion device which converts gravitational energy of elevated water into mechanical work. This mechanical work is converted into electrical energy by means of running an electrical generator. The Pelton turbine was performed in high head and low water flow, in establishment of micro-hydroelectric power plant, due to its simple construction and ease of manufacturing. To obtain a Pelton hydraulic turbine with maximum efficiency during various operating conditions, the turbine parameters must be included in the design procedure. Here all design parameters were calculated at maximum efficiency by using MATLAB SOFTWARE. These parameters included turbine power, turbine torque, runner diameter, runner length, runner speed, bucket dimensions, number of buckets, nozzle dimension and turbine specific speed. The main focus was to design a Pelton Turbine bucket and check its suitability for the the pelton turbine. The literature on Pelton turbine design available is scarce; this work exposes the theoretical and experimental aspects in the design and analysis of a Pelton wheel bucket, and hence the designing of Pelton wheel bucket using the standard rules. The bucket is designed for maximum efficiency. The bucket modelling and analysis was done by using SOLIDWORKS 2015. The material used in the manufacture of pelton wheel buckets is studied in detail and these properties are used for analysis. The bucket geometry is analysed by considering the force and also by considering the pressure exerted on different points of the bucket. The bucket was analysed for the static case and the results of Vonmises stress, Static displacement and Factor of safety are obtained.
Design and Analysis of Low Head, Light weight Kaplan Turbine BladeIRJESJOURNAL
ABSTRACT:- The project deals with the development of the design of low head light weight Kaplan turbine blade. To enhance it's hydrodynamic efficiency by reducing weight, shape alterations, blade angle with combination of materials Aluminium alloy, Structural steel, Titanium alloy Stainless steel. The 3D model of blade is developed using software Solid Works and Analysis of blade is done on Ansys14..
hi, I am sujon I just completed graduate at International University of Business Agriculture and Technology in Bangladesh Department of Mechanical Engineering
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
3. Windmill
Consider the windmill. Rather than the rotor being driven by a
motor, it is rotated in the opposite direction by the wind blowing
through the rotor.
Idealized flow through a windmill: (a) windmill blade geometry;
(b) absolute velocity, V; relative velocity, W, and blade velocity, U
at the inlet and exit of the windmill blade section.
3
5. Angular Momentum Considerations 1/6
Work transferred from a fluid flowing through a turbine
occurs by interaction between moving rotor blades and the
fluid.
Turbine: The torque exerted by the shaft on the rotor is
opposite to the direction of rotation, the energy transfer
is from the fluid to the rotor.
5
6. Angular Momentum Considerations 2/6
All of the turbomachines involve the rotation of an
impeller or a rotor about a central axis, it is appropriate to
discuss their performance in terms of torque and angular
momentum.
6
7. Angular Momentum Considerations 3/6
In a turbomachine a series of particles (a continuum)
passes through the rotor.
For steady flow, the moment of momentum equation
applied to a control volume
( r × F) = ( r × V )ρV ⋅ ndA
∑
∫
CS
Sum of the external torques
Net rate of flow of moment-ofmomentum (angular momentum)
through the control volume
7
8. Angular Momentum Considerations 4/6
Applied to the one-dimensional simplification of flow
through a turbomachine rotor, the axial component
Tshaft = − m1 ( r1Vθ1 ) + m 2 ( r2 Vθ2 )
(2)
Shaft work applied to the contents
Euler turbomachine equation
of the control volume
“+” : in the same direction as rotation
“-” : in the opposite direction as rotation
Euler turbomachine equation : the shaft torque is directly
proportional to the mass flowrate. The torque also depends on the
tangential component of the absolute velocity, Vθ.
8
9. Angular Momentum Considerations 5/6
(2)
W shaft = T shaft ω
(3)
W shaft = − m1 ( U1Vθ1 ) + m 2 ( U 2 Vθ 2 )
Wshaft
w shaft =
= −( U1Vθ1 ) + ( U 2 Vθ2 )
m
(4)
(5)
m = m1 = m 2
(3) (4) (5) :The basic governing equations for pumps or
(3
turbines whether the machines are radial-, mixed, or axial-flow
devices and for compressible and incompressible flows.
9
11. Turbines 1/6
Turbines are devices that extract energy from a flowing
fluid.
The geometry of turbines is such that the fluid exerts a
torque on the rotor in the direction of its rotation.
The shaft power generated is available to derive generators
or other devices.
The two basic types of hydraulic turbines are impulse
and reaction turbines.
11
12. Turbines 2/6
For hydraulic impulse
turbines, the pressure drop
across the rotor is zero; all of
the pressure drop across the
turbine stages occurs in the
nozzle row.
The Pelton wheel is a
classical example of an
impulse turbines.
12
14. Turbines 4/6
For impulse turbines
The total head of the incoming fluid is converted into a
large velocity head at the exit of the supply nozzle.
Both the pressure drop across the bucket (blade) and the
change in relative speed of the fluid across the bucket
are negligible.
The space surrounding the rotor is not completely filled
with fluid.
The individual jets of fluid striking the buckets that
generates the torque.
14
15. Turbines 5/6
For reaction turbines
There is both a pressure drop and a fluid relative speed
change across the rotor.
Guide vanes act as nozzle to accelerate the flow and
turn it in the appropriate direction as the fluid enters the
rotor.
Part of the pressure drop occurs across the guide vanes
and part occurs across the rotor,
15
17. Impulse Turbines 1/6
The easiest type of impulse turbines
design is the Pelton wheel.
Lester Pelton (1829~1908), an
American mining engineer during
the California gold-mining days, is
responsible for many of still-used
features of this type of turbine.
17
18. Impulse Turbines 2/6
A high-speed jet of water strikes the Pelton wheel buckets
and is deflected.
The water enters and leaves the control volume
surrounding the wheel as free jet.
A person riding on the bucket would note that the speed of
the water doest not change as it slides across the buckets.
That is, the magnitude of the relative velocity does not
change, but its direction does.
18
19. Impulse Turbines 3/6
Ideally, the fluid enters and leaves the control volume with
no radial component of velocity.
The buckets would ideally
turn the relative velocity
through a 180º turn, but
physical constraints dictate
that β, the angle of the exit
edge of the blade, is less
than 180 º
19
20. Impulse Turbines 4/6
Flow as viewed by an observer
riding on the Pelton wheel –
relative velocities
Vθ1 = V1 = W1 + U
With W1=W2
(48)
(48)+(49)
Inlet and exit velocity triangles for a
Pelton wheel turbine.
Vθ2 = W2 cos β + U
(49)
Vθ2 − Vθ1 = ( U − V1 )(1 − cos β)
(50)
20
21. Impulse Turbines 5/6
(50)+(2)+(4)
Tshaft = mrm ( U − V1 )(1 − cos β )
Wshaft = Tshaft ω
= mU ( U − V1 )(1 − cos β)
(51)
Typical theoretical and experimental power
and torque for a Pelton wheel turbine as a
function of bucket speed.
21
22. Impulse Turbines 6/6
From above results:
The power is a function of β. A typical value of β=165º
results in a relatively small reduction in power since 1cos165º=1.966.
Although torque is maximum when the wheel is
stopped (U=0), there is no power under this condition –
to extract power one needs force and motion.
The power output is a maximum when U=V/2. (52)
The maximum speed occurs when Tshaft=0.
22
23. Example 12.6 Pelton Wheel Turbine
Characteristics
Water to drive a Pelton wheel is supplied through a pipe from a lake
as indicated in Fig. E12.6a. Determine the nozzle diameter, D1, that
will give the maximum power output. Include the head loss due to
friction in the pipe, but neglect minor losses. Also determine this
maximum power and the angular velocity of the rotor at this
condition.
23
24. Example 12.6 Solution1/3
(51)
Wshaft = ρQU( U − V1 )(1 − cos β )
The nozzle exit speed, V1, can be obtained by applying the
energy equation between a point on the lake surface (where
V0=p0=0) and the nozzle outlet (where z1=p1=0) to give
V12
z0 =
+ hL
2g
V2
hL = f
D 2g
4
D1 V12
113.5
z 0 = 1 + f
=
4
D D 2g
1 + 152 D1
2
Q = πD1 V1 / 4
24
25. Example 12.6 Solution2/3
Wshaft
113.5
U −
=
4
4
1 + 152 D1
1 + 152 D1
2
323UD1
The maximum power occurs when U=V1/2
Wshaft =
2
1.04 × 10 6 D1
4
(1 + 152 D1 ) 3 / 2
The maximum power possible occurs when dWshaft / dD1 = 0
D1=0.239ft
Wshaft =
2
1.04 × 106 D1
4
(1 + 152 D1 ) 3 / 2
= −3.25 × 10 4 ft ⋅ lb / s = −59.0hp
25
26. Example 12.6 Solution3/3
The rotor speed at the maximum power condition can be
obtained from
V1
U = ωR =
2
V1
ω=
= 295rpm
2R
26
27. Example 12.7 Maximum Power Output for a
Pelton Wheel Turbine
Water flows through the Pelton wheel turbine shown in Fig. 12.24.
For simplicity we assume that the water is turned 180º by the blade.
Show, based on the energy equation, that the maximum power
output occurs when the absolute velocity of the fluid exiting the
turbine is zero.
27
28. Example 12.7 Solution1/2
(51)
Wshaft = ρQU( U − V1 )(1 − cos β ) = 2ρQ( U 2 − UV1 )
For this impulse turbine with
β= 180º , the velocity
triangles simplify into the
diagram types shown in Fig.
E12.7. Three possibilities are
indicated:
(a) The exit absolute velocity,
V2, is directed back toward
the nozzle.
28
29. Example 12.7 Solution2/2
(b) The absolute velocity at the exit is zero, or
(c) The exiting stream flows in the direction of the incoming stream.
The maximum power occurs when U=V1/2.
If viscous effects are negligible, when W1=W2 and we have U=W2,
which gives V2=0
Consider the energy equation for flow across the rotor we have
2
p1 V12
p 2 V2
+
+ z1 =
+
+ z 2 + hT + h L
γ
2g
γ
2g
2
V12 − V2
⇒ hT =
− hL
2g
V2=0
29
30. Second Type of Impulse Turbines 1/3
A multinozzle, non-Pelton wheel impulse turbine
commonly used with air as the working fluid.
30
31. Second Type of Impulse Turbines 2/3
A circumferential series of fluid jets
strikes the rotating blades which, as
with the Pelton wheel, alter both the
direction and magnitude of the
absolute velocity.
The inlet and exit pressure are equal.
The magnitude of the relative
velocity is unchanged as the fluid
slides across the blades.
31
32. Second Type of Impulse Turbines 3/3
In order for the absolute velocity of the fluid to be
changed as indicated during its passage across the blade,
the blade must push on the fluid in the direction opposite
of the blade motion.
The fluid pushes on the blade in the direction f the
blades motion – the fluid does work on the blade.
32
33. Example 12.8 Non-Pelton Wheel Impulse
Turbine 1/2
An air turbine used to drive the high-speed drill used by your dentist
is shown in Fig. E12.8a. Air exiting from the upstream nozzle holes
force the turbine blades to move in the direction shown. Estimate
the shaft energy per unit mass of air flowing through the turbine
under the following conditions. The turbine rotor speed is 300,000
rpm, the tangential component of velocity out of the nozzle is twice
the blade speed, and the tangential component of the absolute
velocity out of the rotor is zero.
33
35. Example 12.8 Solution
For simplicity we analyze this problem using an arithmetic mean radius
rm = 1 ( ro + ri )
2
(5)
w shaft = − U1Vθ1 + U 2 Vθ2
Vθ1 = 2 U
Vθ2 = 0
U = ωrm = ... = 394ft / s
w shaft =... = −9640ft ⋅lb / lbm
35
36. Reaction Turbines 1/2
Best suited for higher flowrate and lower head situations
such as are often encountered in hydroelectric power
plants associated with a dammed river.
The working fluid completely fills the passageways
through which it flows.
The angular momentum, pressure, and the velocity of the
fluid decrease as it flows through the turbine rotor – the
turbine rotor extracts energy from the fluid.
36
37. Reaction Turbines 2/2
The variety of configurations: radial-flow, mixed flow,
and axial-flow.
(a) Typical radial-flow
Francis turbine. (b) typical
axial-flow Kaplan turbine.
37
38. Dimensionless Parameters for Turbines 1/2
As with pumps, incompressible flow turbine performance
is often specified in terms of appropriate dimensionless
parameters
The flow coefficient CQ =
Head rise coefficient C H =
Power coefficient
Cp =
Q
ωD 3
gh T
ω2 D 2
Wshaft
ρω3 D 5
38
39. Dimensionless Parameters for Turbines 2/2
On the other head, turbine efficiency is the inverse of
pump efficiency
Wshaft
η=
ρgQh T
39
40. Similarity Laws for Turbines
For geometrically similar turbines and for negligible
Reynolds number and surface roughness difference
effects, the relationship between the dimensionless
parameters are given
C H = φ1 (C Q )
C p = φ 2 (C Q )
η = φ3 (C Q )
40
41. Power Specific Speed 1/2
The design engineer has a variety of turbine types
available for any given application.
It is necessary to determine which type of turbine would
best fit the job before detailed design work is attempted.
As with pump, the use of a specific speed parameter can
help provide this information
N 's =
ω Wshaft / ρ
( gh T )5 / 4
N 'sd =
ω( rpm) Wshaft ( bhp)
[ h T (ft )]5 / 4
(53)
41
42. Power Specific Speed 2/2
Provide a guide for
turbine-type selection.
The actual turbine
efficiency for a given
turbine depends very
strongly on the detailed
design of the turbine.
Typical turbine cross sections and maximum
efficiencies as a function of specific speed.
42
43. Example 12.9 Use of Specific Speed to
Select Turbine Type
A hydraulic turbine is to operate at an angular velocity of 6 rev/s, a
flowrate of 10 ft3/s (0.2832 m3/s), and a head of 20 ft (6.1 m). What
type of turbine should be selected? Explain.
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44. Example 12.9 Solution
ω = 6rev / s = 360rpm
Assumed efficiency
η = 94%
20ft (0.94)
3
3
Wshaft = γQzη = (62.4lb / ft )(10ft / s)
= 21.3hp
550ft ⋅ lb / s ⋅ hp
N 'sd =
ω Wshaft
(hT )
(Fig. 12.32)
5/ 4
= 39.3
A mixed-flow Francis turbine would probably
give the highest efficiency and an assumed
efficiency of 0.94 is appropriate.
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