Buoyancy-driven Flows (CI4-444)

Module aims

  • To provide students with a detailed understanding of fluid motion driven by density differences and its relevance to processes in the atmosphere, rivers, estuaries, seas, buildings etc. and to Civil Engineering calculation and design.
  • The course has a particular emphasis on buoyancy driven flows and turbulent mixing.

Learning outcomes

On successfully completing this course unit, students will be able to: 

  • Understand the basic physics governing a range of buoyancy driven flows.
  • Model gravity currents, plumes and boundary layers.
  • Formulate integral models of volume and buoyancy and apply these to the ventilation of buildings.

Module syllabus

  • Lectures are focused on developing an understanding of buoyancy forces and how the resulting flows are modelled.
  • The coursework for this module consists of a computer laboratory exercise in which the students study data from direct numerical simulation (DNS) of both stratified and unstratified turbulent flow in a channel.  

No.

Topic

Staff

01

Introduction to buoyancy and density-stratification; interfacial gravity waves; shear instability; gravity currents

GH

02

Convection

GH

03

Turbulent flows; the energy cascade and Kolmogorov scales

GH

04

Unstratified and stratified boundary layers

GH

05

Stratified mixing

GH

06

Turbulent plumes in unconfined environments, self-similarity and scaling

JC

07

Turbulent plumes and mixing in confined environments

JC

08

Building ventilation: steady states driven by wind and buoyancy

JC

09

Building ventilation: time-dependent states

JC

10

Revision Lecture

GH, JC

Pre-requisites

MSc: CI9-FM-01, CI9-FM-02, CI9-FM-06

UG: CI1-140, CI2-240, CI3-340

Teaching methods

The lecture format of this module consists of three-hour blocks which are divided approximately equally between lecture and tutorial.

Assessments

Assessment for this module will consist of coursework and a written examination. The coursework will relate to material from either the first (taught by GH) or second (taught by JC) half of the module. Further assessment information will be provided separately.

Module leaders

Professor Graham Hughes