Fluid Mechanics II

Code:

EM0034

Acronym:

MF II

Keywords
Classification	Keyword
OFICIAL	Heat Transfer and Fluid

Instance: 2017/2018 - 1S

Active?	Yes
Responsible unit:	Fluids and Energy Division
Course/CS Responsible:	Master in Mechanical Engineering

Cycles of Study/Courses

Acronym	No. of Students	Study Plan	Curricular Years	Credits UCN	Credits ECTS	Contact hours	Total Time
MIEM	200	Syllabus since 2006/2007	3	-	6	58,5	162

Teaching language

Portuguese

Objectives

Analyse, understand and characterize the behaviour of internal flows, the energetic needs of a fluid flow and the functioning of centrifugal pumps and fans, the measurement of fundamental quantities in fluid flows, the interaction between a moving fluid and an immersed body and some fundamental aspects of compressible flows, in view of solving problems of fluid mechanics in engineering.

Learning outcomes and competences

It is expected that, at the end of the semester, students will be able to/know:
1. The fundamental differences between flows with negligible fluid density variation and compressible flows;
2. Apply the mass conservation and energy equations to viscous flows in pipes, calculate pressure drop, energy needs and available flux, and dimensioning simple pipes and ducts;
3. The fundamental principles of operation and the characteristic curves of centrifugal fans and pumps in view of selecting and analyze the operation of such equipment;
4. The principles of operation and the domains of use of the most common types of speed meters, flow meters and pressure transducers;
5. Understand the essential aspects of flows around immersed bodies and characterize the forces resulting from the interaction flow-body.

Working method

Presencial

Program

COMPRESSIBLE FLOW
Limit of incompressibility. Mach number. Sound propagation and speed of sound. Mach cone. Permanent, adiabatic and isentropic flow. Stagnation properties, critical properties and sonic point.
Isentropic flow with section changes - producing of a supersonic flow.
Critical area, critical pressure and critical mass flux. Choking.
Normal shock wave.

INTERNAL FLOWS
Flow regimes and Reynolds number (rev.).
Entrance length and developed flow. Velocity profiles in pipes.
Head loss in smooth pipes of circular cross section. Darcy-Weisbach equation.
Laminar flow solution.
Turbulent flow. Laminar and turbulent stresses. Turbulent viscosity.
Velocity profile: Wall law, logarithmic overlap law, Blasius law.
Solution of turbulent flow in smooth pipes. Effect of roughness. Colebrook and Haaland equations. Moody chart.
Minor losses in pipes. Loss coefficient and equivalente length.
Losses in non-circular ducts.
Types of problems involving head losses. Flow rate determination. Dimensioning of pipes.
Multiple pipe systems.

CENTRIFUGAL PUMPS AND FANS
Elementary notions of the operation of pumps and fans. Classification. Velocity triangles. Integral estimate of the head and flux of a centrifugal pump.
Characteristic curves of total head, power and efficiency.
Pre-selection of pumps and fans.
Operating point. Stability.
Association pumps in series and in parallel.
Cavitation. Suction capacity of a pump. NPSH

SPEED, FLUX AND PRESSURE MEASUMENTS
Gauge tubes and pressure transducers.
Flow meters of fixed and variable obstruction. Thin-plate orifice. Venturi. Rotameter. Turbine and electromagnetic flow meters.
Pitot tube and Prandtl probe. Thermal, ultrasonic and laser-Doppler anemometry.

EXTERNAL FLOWS
Forces on a body immersed in a flow. Aerodynamic coefficients.
Flow over a flat plate. Boundary layer. Flow regimes.
Laminar boundary layer. Integral estimates and differential formulation. Prandtl / Blasius solution.
Turbulent boundary layer. Approximate solutions. Logarithmic law.
Drag on a flat plate. Influence of surface roughness.
Boundary layer in the presence of a pressure gradient.
Flows around blunt bodies. Drag. Viscous and pressure components.
Lift. Flow around airfoils. Pressure distribution on the surface.
Aerodynamic stall.
Influence of finite span.

Mandatory literature

Bruce R. Munson, ... [et al.]; Fluid Mechanics. ISBN: 978-1-118-31867-6
Frank M. White; Fluid mechanics. ISBN: 978-0-07-128645-9

Teaching methods and learning activities

The course is organized in three classes per week, each one with a duration of 1.5 hour. Two sessions are theoretical and the other one a teoretical-pratical session.

There will be three 2 hour lab session.

keywords

Technological sciences
Physical sciences > Physics > Classical mechanics > Fluid dynamics
Technological sciences > Engineering > Mechanical engineering > Propulsion systems engineering

Evaluation Type

Distributed evaluation with final exam

Assessment Components

Designation	Weight (%)
Exame	60,00
Teste	30,00
Trabalho laboratorial	10,00
Total:	100,00

Amount of time allocated to each course unit

Designation	Time (hours)
Estudo autónomo	101,00
Frequência das aulas	59,00
Trabalho laboratorial	6,00
Total:	166,00

Eligibility for exams

Attendance of, at least, 70% of theoretical-practical and lab sessions.

Calculation formula of final grade

Two theoretical tests, in Moodle platform, one in the middle and the other at the end of the semester. Tests without consultation, 25 minutes in duration.
Written practical examination at the examinations season. Limited consultation (two A4 pages), 120 minutes in duration. A minimum grade of 7/20 is required as the average of the two theoretical tests to have access to this practical test.
The overall grade will be obtained weighting by 30% the average grade in the theoretical tests and by 60% the practical test.


All students must participtate in the laboratory sessions. 

The improvement/final examination includes, as a whole, both theoretical and practical components. The weight of theoretical and practical components will be the same as in the regular examination. No minimum grade in the theoretical component will be required in the improvement/final examination.

Final grade can be adjusted plus or minus 1/20, in function of assiduity, participation in the classes, etc..

Students with marks above 16/20, may have an oral examination.

Examinations or Special Assignments

Not planned.

Internship work/project

Not applicable.

Special assessment (TE, DA, ...)

According to FEUP regulations, with rules similar to the ones of the improvement/final examination.

Classification improvement

According to FEUP regulations, simultaneously with improvement/final examination, with the same rules.

Observations

Language of instruction: Portuguese