04294 - Fluid Mechanics

Learning outcomes

Students learn basic fluid mechanics entailing interdisciplinary knowledge and applications in the fields of Mechanical Engineering.

Course contents

1. Fluids energy, force and power – introduction
   1. Fluid Mechanics
   2. Course objective
   3. Different approaches
   4. Energy conservation in fluids
   5. Newton’s second law and momentum balance
   6. Experimental approach, viscous and turbulent dissipation
   7. Differential equation and simplified solutions for laminar flow
2. Fluids rheology
   1. The mechanics of fluid continuum
   2. Density and specific weight
   3. Vapour pressure and cavitation
   4. Mechanical energy
   5. Bulk modulus
   6. Celerity and Mach’s number
   7. Viscosity
3. Fluid statics
   1. Pressure
   2. Hydrostatic forces
   3. Hydrostatic forces on cylindrical surfaces
   4. Buoyancy
   5. Rigid motion
4. Cinematics and Conservations laws
   1. Fluids cinematics
   2. Substantial derivative
   3. Mass conservation
   4. Bernoulli’s theorem
   5. Pitot’s tube
   6. Flowing through weirs and gates
   7. Energy conservation and Venturi’s tube
   8. Energy line
   9. Euler’s differential equation
   10. Bernoulli’s theorem from Euler’s equation
   11. Pressure distribution across flow lines
5. Integral equations
   1. Control volume
   2. Reynold’s theorem
   3. Mass conservation
   4. Momentum balance
   5. Jet momentum
   6. Flow momentum at bend and junctions in hydraulic pipe systems
   7. Hydraulic machines
6. Energy losses
   1. Laminar and turbulent flows
   2. Reynolds experiment and shear coefficient
   3. Moody’s graph and formulae
   4. Long pipes: shear stress and Darcy’s equation
7. Hydraulic pipe systems
   1. Design and validation
   2. Validation of long pipe
   3. Losses at junctions
   4. Geodetic Head systems
   5. Pump systems
   6. In series and parallel pumps
   7. Minimal suction head
   8. Hydraulic networks
8. Differential equations
   1. Mass conservation
   2. Cauchy’s equation
   3. Rate of strain tensor
   4. Navier-Stokes equation
   5. Laminar flow of viscous fluid: Poisson’s equation
   6. Couette flow
   7. Lubrification

Readings/Bibliography

Yunus A. Cengel, John M. Cimbala. Fluid Mechanics: Fundamentals and Applications (fourth edition) McGraw-Hill Education, 2018.

Teaching methods

 The theoretical part will be presented in face-to-face lessons. This will include the development of graphic examples on the blackboard, and the projecting of slides that will be made available in electronic format.

Assessment methods

The exam consists of a written test and an oral interview. Both cover the entire program.
The written test is preliminary and gives access to the oral inteview. It is conducted online so that the result is available immediately. It consists of three exercises with results to be provided numerically, covering: hydrostatics, ideal fluids, and real fluids. The exercises must be fulfilled in that order for a total time of 20+35+45=100 minutes. Each exercise is worth 100 points, divided into different numerical questions/answers ranging from about 5 to about 15 points each. The maximum score for the written test is therefore 300 points. If the score is above the considered sufficient threshold, the student proceeds to the oral test. The test is considered fully sufficient for a score of 180 or higher, with at least 60 points for each exercise.
Passing the written test is necessary but not enough to pass the exam.
The oral interview will cover not-sufficent excercises and/or the theoretical topics.

The oral exam determines the final grade, which can either increase or lower the score from the written test.

Starting around November, a simulation of the written test is available on Esami On Line. This randomly presents the types of topics that are given in the actual exam. The simulation provides the correct numerical results and can be tried an unlimited number of times. The topics in the simulation and those given in the exam are subject to updates.

Teaching tools

Teaching material such as presentations shown during classes and trials of the final written test will be available at the class pages on

https://virtuale.unibo.it/

https://eol.unibo.it/

Office hours

See the website of Massimo Guerrero