MSc Aerospace Engineering

The unit helps prepare students to tackle and solve a wide range of engineering problems, some of them complex and/or novel.

The aims of the course are to introduce students to: (i) acoustic waves and vibrations in solids and fluids, (ii) the importance of noise and vibrations in engineering systems, (iii) advance analytical methods in acoustics, and (iv) advance analytical methods in vibrations.

Part 1: Acoustics

1.1 Importance/relevance of study of acoustics

1.2 1D acoustic wave propagation • The 1D wave equation in solids and fluids • 1D wave propagation • 1D waves in pipes • 1D wave propagation across impedance changes

1.3 3D acoustic wave propagation • 3D waves in cartesian co-ordinates • Snell’s Law • Ray theory • Cylindrical polar waves • Spherical waves

1.4 Sources of sound • Lighthill’s acoustic analogy • General sources of sound • Sound sources and sinks

Part 2: Advanced Vibrations

2.1 Importance/relevance of study of vibrations

2.2 Vibrations of Multiple Degrees of Freedom Discrete Systems • Equations of motion: Newton's law, D'Alembert's Principle, Lagrange's Equation • Eigenvalue problem: determination of natural frequencies and mode shapes using determinant and matrix iteration methods; determination of intermediate modes using matrix sweeping and deflation methods; eigenvalue approach to normal mode solution • Orthogonality of modes, transformation from physical to modal space/co-ordinates • Proportional and non-proportional damping, static and dynamic coupling • Modal analysis: solving for free and forced vibration via modal co-ordinates, FRF for multiple degree of freedom systems, modal participation factor.

2.3 Vibrations of Continuous Systems • Wave theory: derivations and solutions of wave equations for longitudinal, flexural, torsional, and transverse vibrations for rods and beams • Exact frequency equations; free and forced vibration using closed form solutions • Rayleigh-Ritz approach: free and forced vibration via assumed modes • Flexibility matrix approach; Finite element method.

2.4 Vibration and Shock Control using Viscoelastic and Smart Materials • Viscoelasticity: complex modulus of viscoelastic materials, anti-vibration mounts • Smart materials: electrorheological and magnetorheological fluids, piezoelectric materials, shape memory alloys • Smart structures: collocated sensors and actuators, PZT shunts, active vibration control, semi-active vibration dampers.

Exam - Students are given the opportunity to see their scripts and feedback from the exam sent to them

Report - Feedback is provided in Weeks 10 and 11 of the Semester