Ewch i’r prif gynnwys
 Xander Ramage

Xander Ramage

Research student, Yr Ysgol Mathemateg

Email:
ramagea@cardiff.ac.uk
Location:
M/2.13, 2nd Floor, Mathematics Institute, Senghennydd Road, Cardiff, CF24 4AG, 21-23 Ffordd Senghennydd, Cathays, Caerdydd, CF24 4AG

I work in fluid dynamics and, in particular, the field of hydrodynamic stability theory. In this field, the equations governing fluid flow are simplified in such a way that fast flows in fluids such as water and air are well approximated. Such flows are then perturbed and the behaviour of small disturbances are investigated: if the disturbance grows the flow is unstable and if it decays the flow is stable.

While my studies are conducted in highly idealised mathematical settings, a potential application is in drag reduction in aeroplane flight.

Research interests

  • Theoretical and Computational Fluid Dynamics.
  • In particular Hydrodynamic stability and numerical simulation of periodic flows.

Research group

Thesis

Linear disturbance evolution in the semi-infinite Stokes layer and related flows

This work is concerned with the evolution of linear disturbances in temporally periodic flows of newtonian fluids.


By utilising a linear stability analysis that takes account of the periodicity through Floquet theory and direct numerical simulation of the linearised governing equations, the impulse response of such flows are studied. The pure Stokes layer, being the flow generated above an oscillating plate, is of particular interest.


The flow is shocked at some location and the behaviour of thie impulse response is explored. By studying the asymptotic behaviour at fixed spatial locations, I have provided insight into the family-tree structure of wavepackets observed in previous work.

Funding source

EPSRC

Photograph of Nikos Savva

Dr Nikos Savva

Lecturer in Applied Mathematics

2017

2016

  • Davies, C., Thomas, C. and Ramage, A. 2016. Impulsively excited disturbances in non-uniform boundary layers. Presented at: 20th Australasian Fluid Mechanics Conference, University of Western Australia, Perth, Australia, December 2016Proceedings of the 20th Australasian Fluid Mechanics Conference. http://people.eng.unimelb.edu.au/imarusic/proceedings/20%20AFMC%20TOC.htm: Australasian Fluid Mechanics Society