units

MEC3451

Faculty of Engineering

# Undergraduate - UnitMEC3451 - Fluid mechanics II

This unit entry is for students who completed this unit in 2015 only. For students planning to study the unit, please refer to the unit indexes in the the current edition of the Handbook. If you have any queries contact the managing faculty for your course or area of study. print version

## 6 points, SCA Band 2, 0.125 EFTSL

Refer to the specific census and withdrawal dates for the semester(s) in which this unit is offered.

 Level Undergraduate Faculty Faculty of Engineering Organisational Unit Department of Mechanical and Aerospace Engineering Offered Clayton First semester 2015 (Day)Malaysia First semester 2015 (Day) Coordinator(s) Dr P Ranganathan (Clayton); Dr Tan Ming Kwang (Malaysia)

### Synopsis

The foundations of continuum analysis of fluids will be presented. Using control volume analysis the fundamental conservation laws for mass, momentum and energy are developed leading to the derivation of the Navier-Stokes equations. Techniques employed to solving these equations for specific problems are explored. Methods of exact and approximate solutions of these equations, and the use of conceptual and analytical tools such as flow similitude, vorticity, circulation, stream function and velocity potential are described. The concept of boundary layers and its use in the calculation of drag and lift forces is elucidated. The origins and physical consequences of the phenomenon of fluid turbulence are discussed, along with their implications for computation of turbulent flows. The analysis of compressible flows and its applications are discussed. The Unit introduces the concepts underpinning the broad areas of fluid acoustics, computational fluid dynamics, environmental fluid mechanics and wind energy.

### Outcomes

• to understand and apply definitions of measures of fluid motion (i.e. its kinematics) such as streamlines, streaklines and pathlines, the velocity gradient tensor and its decomposition into components describing vorticity, deformation and volume dilatation;
• to be able to apply techniques of control volume analysis and fundamental principles of mass, momentum and energy conservation to obtain the Navier-Stokes equations describing spatiotemporal evolution of density, pressure, temperature, and velocity fields;
• to understand common boundary conditions for the Navier-Stokes equations and apply them to obtain analytical solutions for specific cases such as simple laminar flows;
• to be able to apply similitude analysis to the Navier-Stokes equations, and identify limiting cases governed by Stokes and Euler equations for creeping flow and inviscid flows, respectively;
• to appreciate the significant role of computational fluid dynamics (CFD) in engineering applications of fluid mechanics, and understand how analytical methods complement CFD practice by providing physical insight into fluid behaviour;
• to be able to solve potential flow problems, by applying the concept of the superposition principle on stream function or velocity potential, along with the Bernoulli equation;
• to understand the classical and modern descriptions of turbulence respectively as noisy flow, and unstable flow with vortical structure across several length and time scales.
• to identify and characterise turbulence flows, understand the concept of turbulent viscosity to account for the effect of energy dissipation in turbulence, and its implications for turbulence modelling in computational fluid dynamics;
• to understand and apply the Prandtl-Blasius and von-Karman approaches to obtaining boundary-layer thickness and flow profiles in laminar boundary layers; to understand the effect of favourable and adverse pressure gradients on boundary layer flows and boundary layer separation
• to understand the applications that exploit drag reduction by inducing boundary layer for wake suppression;
• to understand lift generation in streamlined flows past objects and understand the strategies to manipulate lift
• to be able to apply isentropic analysis to high-speed compressible flows of ideal gases, and understand stationary and moving normal shocks;
• to be aware of applications of compressible flow analysis in rocket nozzles, supersonic flight and in fluid acoustics.

### Assessment

Practice classes: 10%
Assignment, projects: 20%
Examination (3 hours): 70%

Note that students are required to achieve at least 45% in the total continuous assessment component (assignments, tests, mid-semester exams, laboratory reports) and at least 45% in the final examination component and an overall mark of 50% to achieve a pass grade in the unit. Students failing to achieve this requirement will be given a maximum of 45% in the unit

6 hours of contact time per week (3 hours lectures and 3 hours practice sessions) and 6 hours of private study per week 