This document provides information about dimensional analysis and model studies in fluid mechanics. It defines dimensional analysis as a technique that uses the study of dimensions to help solve engineering problems. Buckingham π theorem is discussed, which states that physical phenomena with n variables can be expressed in terms of n-m dimensionless terms, where m is the number of fundamental dimensions. Several model laws are defined, including Reynolds, Froude, Euler, and Weber laws. Hydraulic models are classified as undistorted or distorted, and scale effects are discussed.
1. Introduction to Kinematics
2. Methods of Describing Fluid Motion
a). Lagrangian Method
b). Eulerian Method
3. Flow Patterns
- Stream Line
- Path Line
- Streak Line
- Streak Tube
4. Classification of Fluid Flow
a). Steady and Unsteady Flow
b). Uniform and Non-Uniform Flow
c). Laminar and Turbulent Flow
d). Rotational and Irrotational Flow
e). Compressible and Incompressible Flow
f). Ideal and Real Flow
g). One, Two and Three Dimensional Flow
5. Rate of Flow (Discharge) and Continuity Equation
6. Continuity Equation in Three Dimensions
7. Velocity and Acceleration
8. Stream and Velocity Potential Functions
Topics:
1. Introduction to Fluid Dynamics
2. Surface and Body Forces
3. Equations of Motion
- Reynold’s Equation
- Navier-Stokes Equation
- Euler’s Equation
- Bernoulli’s Equation
- Bernoulli’s Equation for Real Fluid
4. Applications of Bernoulli’s Equation
5. The Momentum Equation
6. Application of Momentum Equations
- Force exerted by flowing fluid on pipe bend
- Force exerted by the nozzle on the water
7. Measurement of Flow Rate
a). Venturimeter
b). Orifice Meter
c). Pitot Tube
8. Measurement of Flow Rate in Open Channels
a) Notches
b) Weirs
1. Introduction to Kinematics
2. Methods of Describing Fluid Motion
a). Lagrangian Method
b). Eulerian Method
3. Flow Patterns
- Stream Line
- Path Line
- Streak Line
- Streak Tube
4. Classification of Fluid Flow
a). Steady and Unsteady Flow
b). Uniform and Non-Uniform Flow
c). Laminar and Turbulent Flow
d). Rotational and Irrotational Flow
e). Compressible and Incompressible Flow
f). Ideal and Real Flow
g). One, Two and Three Dimensional Flow
5. Rate of Flow (Discharge) and Continuity Equation
6. Continuity Equation in Three Dimensions
7. Velocity and Acceleration
8. Stream and Velocity Potential Functions
Topics:
1. Introduction to Fluid Dynamics
2. Surface and Body Forces
3. Equations of Motion
- Reynold’s Equation
- Navier-Stokes Equation
- Euler’s Equation
- Bernoulli’s Equation
- Bernoulli’s Equation for Real Fluid
4. Applications of Bernoulli’s Equation
5. The Momentum Equation
6. Application of Momentum Equations
- Force exerted by flowing fluid on pipe bend
- Force exerted by the nozzle on the water
7. Measurement of Flow Rate
a). Venturimeter
b). Orifice Meter
c). Pitot Tube
8. Measurement of Flow Rate in Open Channels
a) Notches
b) Weirs
Dimensional analysis Similarity laws Model laws R A Shah
Rayleigh's method- Theory and Examples
Buckingham Pi Theorem- Theory and Examples
Model and Similitude
Forces on Fluid
Dimensionless Numbers
Model laws
Distorted models
Offshore structures are continuously exposed to extremely varying aerodynamic
and hydrodynamic loads. The storm waves and breaking waves may cause significant
impact on coastal and offshore structures such as vertical sea wall, wind turbines,
LNG carriers and submarine pipelines etc. The prediction of the breaking wave
impact pressure is the important aspect in the design of those structures. The breaking
wave forces produce the highest hydrodynamic loads on substructures in shallow
water, predominantly plunging breaking waves. Owing to the complex and transient
nature of the impact forces it requires more details concerning the physics of breaking
waves and nature of wave interaction with those structures.
In this paper, A Piston-type wave generator was incorporated in the
computational domain to generate waves. Flow 3D was used for simulating 3D
numerical wave tank. The desired breaking waves are simulated using the concept of
wave focusing using Flow 3D solver. These waves are made to impinge on the elastic
circular cylinders of different materials such as PVC, timber and concrete by varying
the support conditions such as cantilever, both ends fixed, inclined support with 30º
inclination. The hydrodynamic response and the structural response are analysed and
validated with the experimental literatures. The maximum impact pressure transpired
on the cylinder due to plunging wave impact from numerical simulation is found to be
eight times of the non-breaking waves
Unit 5 Open Channel flowUnit 5 Open Channel flowUnit 5 Open Channel flowUnit 5 Open Channel flowUnit 5 Open Channel flowUnit 5 Open Channel flowUnit 5 Open Channel flowUnit 5 Open Channel flow
Stability and surface free energy analysis of a liquid drop on a horizontal c...eSAT Journals
Abstract The stable conformation of a liquid-water drop on a horizontal cylindrical wire is studied. The stable conformation is established with various wire diameters. For each conformation of the drop the surface free energy is calculated using FEM simulation. The free energy for different drop shapes are compared with consideration to different volumes and contact angles. The effect of gravity on droplet shape with respect to wire diameter and droplet volume is observed. The droplet configurations under the influence of gravity and in the absence of gravity are observed and the shapes are described through coordinates of liquid-air and liquid-solid interfaces. The compensation of one interfacial energy with that of another is found. The wetting behaviour of liquid–drop on a wire is found to be significantly different from that on a plane surface under the influence of wire geometry. The numerical model was established taking liquid density at 1000kg/m3 and gravitational acceleration at 9.8 m/s2.The numerical study is important in understanding the spreading of liquid droplets over cylindrical surfaces .The spreading of liquid over surfaces has got wide application in food industry, micro fluidics and more and in understanding the coating behaviour, liquid-solid and liquid-vapour interactions, material properties, etc. Keywords: Surface Free Energy, FEM Simulation, Contact angle, Gravity
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Comparision of flow analysis through a different geometry of flowmeters using...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
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UNIT V : DIMENSIONAL ANALYSIS AND MODEL STUDIES
1. Define dimensional analysis.
Dimensional analysis is a mathematical technique which makes use of the study
of dimensions as an aid to solution of several engineering problems. It plays an
important role in research work.
2.Write the uses of dimension analysis?
• It helps in testing the dimensional homogeneity of any equation of fluid motion.
• It helps in deriving equations expressed in terms of non-dimensional parameters.
• It helps in planning model tests and presenting experimental results in a systematic
manner.
3.List the primary and derived quantities.
Primary or Fundamental quantities: The various physical quantities used to
describe a given phenomenon can be described by a set of quantities which are
independent of each other. These quantities are known as fundamental quantities or
primary quantities. Mass (M), Length (L), Time (T) and Temperature (θ) are the
fundamental quantities.
Secondary or Derived quantities: All other quantities such as area, volume,
velocity, acceleration, energy, power, etc are termed as derived quantities or
secondary quantities because they can be expressed by primary quantities.
4. Write the dimensions for the followings.
Dynamic viscosity (μ) – ML-1
T-2
Mass density (ρ) – ML-3
,
Force (F) - MLT-2
,
Power (P) - ML2
T-3
5. Define dimensional homogeneity.
An equation is said to be dimensionally homogeneous if the dimensions of the
terms on its LHS are same as the dimensions of the terms on its RHS.
6. Mention the methods available for dimensionalanalysis.
Rayleigh method,
Buckinghum π method
7.State Buckingham’s π theorem.
It states that “if there are ‘n’ variables (both independent & dependent variables)
in a physical phenomenon and if these variables contain ‘m’ functional dimensions
and are related by a dimensionally homogeneous equation, then the variables are
arranged into n-m dimensionless terms. Each term is called π term”.
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8. List the repeating variables used in Buckingham π theorem.
Geometrical Properties – l, d, H, h, etc,
Flow Properties – v, a, g, ω, Q, etc,
Fluid Properties – ρ, μ, γ, etc.
9. Define model and prototype.
The small scale replica of an actual structure or the machine is known as its
Model, while the actual structure or machine is called as its Prototype. Mostly
models are much smaller than the corresponding prototype.
10.Write the advantages of model analysis.
Model test are quite economical and convenient.
Alterations can be continued until most suitable design is obtained.
Modification of prototype based on the model results.
The information about the performance of prototype can be obtained well in
advance.
11.List the types of similarities or similitude used in model anlaysis.
a) Geometric similarities,
b) Kinematic similarities,
c) Dynamic similarities
12. Define geometric similarities
It exists between the model and prototype if the ratio of corresponding lengths,
dimensions in the model and the prototype are equal. Such a ratio is known as
“Scale Ratio”.
13. Define kinematic similarities
It exists between the model and prototype if the paths of the homogeneous
moving particles are geometrically similar and if the ratio of the flow properties is
equal.
14. Define dynamic similarities
It exits between model and the prototype which are geometrically and kinematic
similar and if the ratio of all forces acting on the model and prototype are equal.
15.Mention the various forces considered in fluid flow.
Inertia force,
Viscous force,
Gravity force,
Pressure force,
Surface Tension force,
Elasticity force
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16.Define model law or similarity law.
The condition for existence of completely dynamic similarity between a model
and its prototype are denoted by equation obtained from dimensionless numbers.
The laws on which the models are designed for dynamic similarity are called Model
laws or Laws of Similarity.
17.List the various model laws applied in model analysis.
Reynold’s Model Law,
Froude’s Model Law,
Euler’s Model Law,
Weber Model Law,
Mach Model Law
18.State Reynold’s model law
For the flow, where in addition to inertia force the viscous force is the only other
predominant force, the similarity of flow in the model and its prototype can be
established, if the Renold’s number is same for both the systems. This is known as
Reynold’s model law. Re(p) = Re(m)
19. State Froude’s model law
When the forces of gravity can be considered to be the only predominant force
which controls the motion in addition to the force of inertia, the dynamic similarities
of the flow in any two such systems can be established, if the Froude number for
both the system is the same. This is known as Froude Model Law. Fr(p)
= Fr (m)
20. State Euler’s model law
In a fluid system where supplied pressures are the controlling forces in addition
to inertia forces and other forces are either entirely absent or in-significant the
Euler’s number for both the model and prototype which known as Euler Model Law.
21. State Weber’s model law
When surface tension effect predominates in addition to inertia force then the
dynamic similarity is obtained by equating the Weber’s number for both model and
its prototype, which is called as Weber Model Law.
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22. State Mach’s model law
If in any phenomenon only the forces resulting from elastic compression are
significant in addition to inertia forces and all other forces may be neglected, then
the dynamic similarity between model and its prototype may be achieved by
equating the Mach’s number for both the systems. This is known Mach Model Law.
23.Classify the hydraulic models.
The hydraulic models are classified as: Undistorted model & Distorted model
24.Define undistorted model
An undistorted model is that which is geometrically similar to its prototype, i.e.
the scale ratio for corresponding linear dimensions of the model and its prototype are
same.
25. Define distorted model
Distorted models are those in which one or more terms of the model are not
identical with their counterparts in the prototype.
26. Define Scale effect
An effect in fluid flow that results from changing the scale, but not the shape, of
a body around which the flow passes.
27.List the advantages of distorted model.
• The results in steeper water surface slopes and magnification of wave heights in
model can be obtained by providing true vertical structure with accuracy.
• The model size can be reduced to lower down the cast.
• Sufficient tractate force can be developed to produce bed movement with a small
model.
28.Write the dimensions for the followings.
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PART - B
1. Explain Buckingham’s theorem.
2. The resisting force (R) of a supersonic flight can be considered as dependent upon
length of aircraft (l), velocity (V), air viscosity ‘μ’, air density ‘ρ’, and bulk modulus
of air ‘ k’. Express the functional relationship between these variables and the
resisting force.
3. A ship is 300 m long moves in sea water, whose density is 1030 kg/m3. A 1:100
model of this to be tested in a wind tunnel. The velocity of air in the wind tunnel
around the model is 30 m/s and the resistance of the model is 60 N. Determine the
velocity of ship in sea water and also the resistance of the ship in sea water. The
density of air is given as 1.24 kg/m3. Take the Kinematic viscosity of sea water and
air as 0.012 stokes and 0.018 stokes respectively.
4. A 7.2 m height and 15 m long spillway discharge 94 m3/s, under a head of 2.0m. If a
1:9 scale model of this spillway is to be constructed, determine model dimensions,
head over spillway model and the model discharge. If model experience a force of
7500 N (764.53 Kgf), determine force on the prototype.
5. A quarter scale turbine model is tested under ahead of 12 m. The full scale turbine is
to work under a head of 30 m and to run at 428 rpm. Find N for model. If model
develops 100 kW and uses 1100 l/s at this speed, what power will be obtained from
full scale turbine assuming its n is 3% better than that of model.
6. Using Buckingham’s π theorem, show that the drag force FD = ρ L2V2φ (Re,M)
which Re = ρ LV/μ; M = V/C; ρ = fluid mass density; L = chord length: V= velocity
of aircraft; μ = fluid viscosity; C = sonic velocity = √K/ ρ where K = bulk modulus of
elasticity.
7. The resistance ‘ R’ experienced by apartially, submerged body depends upon the
velocity ‘V’, length of the body ‘l’, viscosity of fluid ‘μ’, density of the fluid ‘ρ’, and
gravitational acceleration ‘g’; obtain expression for R.
8. Derive the relation using Buckingham’s π theorem F = ρ U2D2f (μ/UD ρ), ND/U).
9. State the reasons for construction distorted model of rivers and discuss the various
types of distortion in models. What are the merits and demerits of distorted models
as compared to undistorted model?
10. In an aeroplane model of size 1/10 of its prototype the pressure drop is 7.5 kN/m3.
The model is tested in water. Find the corresponding pressure drop in the prototype.
Take density of air is 1.4 kg/ m3, density of water is 1000 kg/ m3, viscosity of air is
0.00018 poise and viscosity of water is 0.01 poise.