Review Lecture

M.J. Cleary AMME2261 FLUID MECHANICS 1 2015

AMME2261 / 9261 Fluid Mechanics 1

Review Lecture

Semester 1, 2015

Course Aims

M.J. Cleary AMME2261 FLUID MECHANICS 1 2015 I

When you complete this unit of study you will have:

an understanding of the basic equations governing the statics and dynamics of fluids;

the ability to analyze and determine the forces applied by a static fluid;

the ability to evaluate the relevant flow parameters for fluid flow in internal engineering systems such as pipes and pumps (velocities, losses, etc.) and external systems such as flow over wings and airfoils (lift and drag).

Course content includes basic concepts of:

viscosity, density, continuum, pressure, force, buoyancy, acceleration, continuity, conservation of momentum, streamlines, Bernoulli equation, Euler equation, Navier-Stokes equation.

Experiments introduce methods of flow observation.

Topics

M.J. Cleary AMME2261 FLUID MECHANICS 1 2015

Topic Weeks Chapter in text

Module 1: Introduction & Fluid Properties 1 1, 2

Module 2: Fluid Statics, Buoyancy and Stability 2 - 4 3

Module 3: Fundamentals of Fluid Dynamics 5 - 7 4, 5

Module 4: Applied Fluid Dynamics 1 dimensional analysis 8 7

Module 5: Applied Fluid Dynamics 2 inviscid flows 9 - 11 6

Module 6: Applied Fluid Dynamics 3 simple viscous flows 12 - 13 8, 9

Review lecture

Module 1: Introduction & Fluid Properties


1. scope of fluid mechanics

2. the definition of a fluid

3. methods of analysis

4. dimensions and units

very important for dimensional analysis

5. fluid as a continuum

6. viscosity

shear stress, torque on journal bearing, pipe wall stress, Couette flow

7. surface tension

capillary rise/fall

Past exam questions: 2012 Q1 2013 Q1 2014 Q8

Module 2: Fluid Statics, Buoyancy and Stability


1. Derivation of an equation for pressure pressure variation through an atmosphere,

variation with altitude, standard atmosphere

2. Hydraulic pressure and manometers pressure difference, summing pressures through a manometer,

differentiating between pressure change due to wall friction and pressure change due to altitude change, calculating forces on hydraulic jacks

3. Hydrostatic forces on submerged surfaces methods of calculation (integrate fundamental form or remember

algebraic expressions), tabulated 1st and 2nd moments of area, parallel axis theorem

plane & curved surfaces of different shapes

4. Buoyancy and stability displacement, waterline depth, numerical integration, metacentric height

and criterion for stability

Past exam questions: 2012 Q2,Q9 2013 Q2,Q9 2014 Q3

Module 3: Fundamentals of Fluid Dynamics


Part A: Integral Forms of Governing Equations

1. Conservation of mass (continuity)

2. Conservation of linear momentum

3. Conservation of angular momentum

numerous examples in class, tutorials and practice problems

forces on pipe couplings, drag on simple objects

know how to locate a control surface to simplify analysis

Past exam questions: 2012 Q3,Q10 2013 Q3,Q10 2014 Q6,Q9

Module 3: Fundamentals of Fluid Dynamics


Part B: Differential Forms of Governing Equations

1. When to use differential forms of the governing equations

2. Conservation of mass

permissible velocity fields

3. Conservation of momentum (Navier-Stokes and Euler equations)

solution possible for very simple cases, know how to simplify the equations (removing terms)

may be required to solve one-dimensional differential equations


Module 4: Applied Fluid Dynamics 1 dimensional analysis


1. Experimental fluid mechanics

2. The Buckingham Pi Theorem

Know how to use it. Many examples. Quiz 3.

3. Determining non-dimensional groups

4. Significant non-dimensional groups

Reynolds number for viscous flows

Froude number for gravitational flows (e.g. a ships wake)

5. Flow similarity and model experiments

dynamic similarity between model and prototype

Past exam questions: 2012 Q5 2014 Q4,Q10

Module 5: Applied Fluid Dynamics 2 inviscid flows


Part A: Euler Equation

1. Navier-Stokes equation with viscous stress terms removed

obtain solutions to differential equations e.g. flow over cylinder

2. Euler Equation along and transverse to a streamline

What is a streamline?

concepts related to velocity/pressure coupling, pressure change normal to a streamline

Past exam questions: 2012 Q7,Q10



Part B: Bernoulli Equation

1. Derivation of the Bernoulli Equation

for exam know how to use Bernoulli equation

know the limitations of Bernoulli equation (steady, inviscid, incompressible, along a streamline)

concept of streamlines, ideal inviscid flow over cylinder/sphere

2. Static, stagnation and dynamic pressures

calculation of pressure at leading edge stagnation point, minimum/maximum pressure on the surface of a wing etc.

3. Calculation of velocity from pressure measurements (pitot-static system)




Part C: Potential Flow Theory

1. Definitions of stream and potential functions

integrate to obtain velocities

Cartesian and polar coordinates

definitions will be given to i.e.

2. Laplaces Equation

3. Plane elementary flows

know what uniform flow, source, sink, irrotational vortex and doublet look like

do not need to remember stream and potential functions, they will be given

4. Superposition of plane elementary flows to create comple

Rankine body flow, etc. Past exam questions: new topic this year

yv

xu

=

=

=

=r

Vr

Vr1

xv

yu

=

=

rV

rVr

=

=

1



Part D: Turbomachinery

1. Euler turbomachine equations

velocity diagrams, shockless flow (blade angles and pump speed) torque, power and head calculations


Module 6: Applied Fluid Dynamics 2 simple viscous flows


1. Introduction to internal viscous flows

concept of entrance length, Reynolds number dependence

2. Fully developed laminar pipe flow

parabolic velocity profile, mean velocity, pressure loss as function of volumetric flow rate

3. Introduction to external viscous flows

4. Flow over immersed bodies, lift and drag

viscous and pressure drag, flow separation

drag coefficient empirical values, Stokes flow

terminal velocity / static equilibrium

lift, basic concepts, lift coefficient Past exam questions: 2012 Q3,Q8 2013 Q3,Q7,Q8 2014 Q1,Q6

The Exam


Two sections: Part A multiple choice, 8 questions, 7 marks each, answer all 8

questions

Part B worked solutions, 2 questions, 22 marks each, part-marks will be awarded, answer both questions

10 minutes reading time and 2 hours writing time.

Question style similar to lecture examples, in-class assignments, quizzes and past exams.

Note that exams in 2012, 2013 and 2014 were 1.5 hours. More depth to questions this year.

Exam Front Page and Formulae Sheet are available on Blackboard.

Last two years exam also available on Blackboard (will not be making solutions available).

The Exam


Exam Front Page Formulae

AMME2261 / 9261 Fluid Mechanics 1Review LectureCourse AimsTopicsModule 1: Introduction & Fluid PropertiesModule 2: Fluid Statics, Buoyancy and StabilityModule 3: Fundamentals of Fluid DynamicsModule 3: Fundamentals of Fluid DynamicsModule 4: Applied Fluid Dynamics 1 dimensional analysisModule 5: Applied Fluid Dynamics 2 inviscid flowsModule 5: Applied Fluid Dynamics 2 inviscid flowsModule 5: Applied Fluid Dynamics 2 inviscid flowsModule 5: Applied Fluid Dynamics 2 inviscid flowsModule 6: Applied Fluid Dynamics 2 simple viscous flowsThe ExamThe Exam

Review Lecture

Documents

Transcript of Review Lecture