Student Records
Programme & Unit Catalogues

## ME40328: Turbulence and noise

Owning Department/School: Department of Mechanical Engineering
Credits: 6
Level: Masters UG & PG (FHEQ level 7)
Period: Semester 1
Assessment: EX 100%
Supplementary Assessment: Like-for-like reassessment (where allowed by programme regulations)
Requisites:
Description: Aims:
To give students an understanding of the quantitative analysis of turbulence in engineering flows.
To give students the ability to analyze aerodynamically generated noise radiated from engineering systems.

Learning Outcomes:
After taking this unit the student should be able to:
Perform basic analyses of turbulent flows, using appropriate mathematical and statistical methods; perform basic calculations of noise under suitable approximations; discuss turbulence, noise and their interaction in real engineering systems.

Skills:
Problem solving; numeracy; working independently.

Content:
The Navier-Stokes equations, non-dimensionalization, qualitative description of turbulence. Reynolds averaged Navier Stokes equations, Reynolds stresses, turbulent viscosity, Prandtl mixing length hypothesis. Free shear flows, turbulent length and time scales, kinetic energy and the Kolmogorov spectrum. Turbulent boundary layers. The wave equation in three dimensions: spherical and plane waves. Frequency and time domain representations, spectral and statistical analysis of signals: power- and cross-spectrum, correlation and coherence. Modification of sound fields: reflection by hard, soft and finite impedance walls. Source mechanisms and directivity: monopole, dipole and quadrupole. Sound generation by solid bodies: pulsating sphere, circular piston. Sound from rotating systems, application to propellers and rotors. Acoustic fields in circular ducts, plane and higher order modes. Radiation from circular ducts, application to aircraft engine noise. Turbulent jets Lighthill's acoustic analogy, eighth power law. Far-field noise cross-spectrum from turbulent jets. Boundary layer noise. Vortex dynamics and the Biot-Savart law; vortex ring interactions, leapfrogging. Coherent structures in turbulence and noise generation.
Programme availability:

#### ME40328 is Optional on the following programmes:

Department of Mechanical Engineering
• UEME-AFM04 : MEng (hons) Aerospace Engineering (Full-time) - Year 4
• UEME-AKM04 : MEng (hons) Aerospace Engineering (Full-time with Thick Sandwich Placement) - Year 5
• UEME-AFM05 : MEng (hons) Aerospace Engineering with French (Full-time) - Year 4
• UEME-AKM05 : MEng (hons) Aerospace Engineering with French (Full-time with Thick Sandwich Placement) - Year 5
• UEME-AFM06 : MEng (hons) Aerospace Engineering with German (Full-time) - Year 4
• UEME-AKM06 : MEng (hons) Aerospace Engineering with German (Full-time with Thick Sandwich Placement) - Year 5

Notes:
* This unit catalogue is applicable for the 2012/13 academic year only. Students continuing their studies into 2013/14 and beyond should not assume that this unit will be available in future years in the format displayed here for 2012/13.
* Programmes and units are subject to change at any time, in accordance with normal University procedures.
* Availability of units will be subject to constraints such as staff availability, minimum and maximum group sizes, and timetabling factors as well as a student's ability to meet any pre-requisite rules.