1 Basic Fluid Mechanics Dr. Peter J. Disimile “Dr.D” Department of Aerospace Engineering [email protected]Chapter 1 Introduction 1 4/16/2018 Chapter 1A: Introduction Why Study Fluid Mechanics? It impacts every aspect of our life from weather to transportation, the environment to physiology, from sports and recreation, etc. Some examples follow: Chapter 1 Introduction 2 4/16/2018
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Basic Fluid Mechanics - ase.uc.edupdisimil/classnotes/Bas Fluid Mech... · fluid mechanics problems using control volume and differential analysis: - Exact solutions only exist for
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It impacts every aspect of our life from weather to transportation, the environment to physiology, from sports and recreation, etc. Some examples follow:
Chapter 1 Introduction 24/16/2018
2
Weather & Climate
Tornado
Hurricane
Global Climate
Thunderstorm
Chapter 1 Introduction 34/16/2018
4/16/2018 Chapter 1 Introduction 4
Vehicles
Aircraft
SubmarinesHigh-speed rail
Surface ships
3
4/16/2018 Chapter 1 Introduction 5
EnvironmentMan made Air Pollution
Volcanic Eruption
River Hydraulics
4/16/2018 Chapter 1 Introduction 6
Physiology and Medicine
Blood pump
Ventricular assist device
Waste Fluid Flow
4
4/16/2018 Chapter 1 Introduction 7
Sports & Recreation
Water sports
Auto racing
Offshore racingCycling
Surfing
Chapter 1A: Introduction
(AFD)(EFD)(CFD)
Chapter 1 Introduction 84/16/2018
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Chapter 1A: Solution Methods
Analytical FD - The mathematical solution of fluid mechanics problems using control volume and differential analysis:
- Exact solutions only exist for simple geometries and boundary conditions.
- Approximate solutions exist for linear problems and those which utilize empirical correlations obtained from experiments.
Chapter 1 Introduction 94/16/2018
Analytical Fluid Dynamics
Laminar pipe flow - simplify the momentum equation, integrate, and apply boundary conditions.
Exact solution :
2 21( ) ( )( )4
pu r R rx
Assume:
xgy
u
x
u
x
p
Dt
Du
2
2
2
2
0
00
Chapter 1 Introduction 104/16/2018
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Experimental FD - Using experimental methods and procedures to solve fluid mechanic phenomena on both small scale models and full scale systems.
• This requires the use of measurement systems, uncertainty analysis, and similarity.
• Measurement systems require calibrated sensors and data acquisition systems.
Experimental Fluid Dynamics
Chapter 1 Introduction 114/16/2018
Experimental Fluid Dynamics
Chapter 1 Introduction 124/16/2018
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Flow with particles
d (known)
Velocity = distance/time
t (measured)
Signal
Time
LaserBraggCell backscattered light
measuring volume
Detector
Processor
Laser Doppler Anemometry (LDA)
Experimental Fluid Dynamics
Chapter 1 Introduction 134/16/2018
Flow is seeded with micron sized particles, scattered laser light is collected, and velocity calculated.
Experimental Fluid Dynamics
Chapter 1 Introduction 144/16/2018
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Velocity Profile 2.5cm Upstream of Inlet Cone
0
5
10
15
20
25
0 20 40 60 80 100 120
Distance across the pipe diameter (mm)
Me
an
Ve
loc
ity
(m
/s)
Blue component Green Component
Experimental Fluid Dynamics
Chapter 1 Introduction 154/16/2018
Computational FD - Using computational methods the governing equations and boundary conditions are solved numerically.
This involves the use of equation solvers and grid generation techniques.
Computational Fluid Dynamics
Chapter 1 Introduction 164/16/2018
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Viscous Model
Boundary Conditions
Initial Conditions
Convergent Limit
Contours
Precisions(single/double)
Numerical Scheme
Vectors
StreamlinesVerification
Geometry
Select Geometry
Geometry Parameters
Physics Mesh Solve Post-Processing
CompressibleON/OFF
Flow properties
Unstructured(automatic/
manual)
Steady/Unsteady
Forces Report(lift/drag, shear stress, etc)
XY Plot
Domain Shape and Size
Heat Transfer ON/OFF
Structured(automatic/
manual)
Iterations/Steps
Validation
Reports
Computational Fluid Dynamics
Chapter 1 Introduction 174/16/2018
Vulcan Geometry, Grid, and Location of Planes
CoreInlet Pipe
Detailed view of planes 3 and 4
3 4
Z
Y
X
Computational Fluid Dynamics
Chapter 1 Introduction 184/16/2018
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Example of Grid Used by CFD-ACE
Start of coreexpansion
Constant axialgrid slice
End of nacelle expansion, andend of core expansion