I am happy to consider applications from students wishing to study for a PhD with me on any of my research interests. In addition, there may be specific projects for which I am keen to attract students. Details of these projects can be found below.

I am more than happy to talk to potential applicants, so please get in touch with me for more information. For instructions on how to make a formal application, please see the UEA Maths Research Degrees page.

Flow-induced oscillations of fluid-conveying elastic vessels arise in many engineering and biomechanical systems. Examples include pipe flutter, wheezing during forced expiration from the pulmonary airways, and the development of Korotkoff sounds during blood pressure measurement by sphygmomanometry.

Experimental studies of flow in collapsible tubes are typically performed with a Starling resistor. A finite-length elastic tube is mounted between two rigid tubes and flow is driven through the system. The collapsible segment is contained inside a pressure chamber which allows the external pressure acting on the elastic tube to be controlled. If the pressure outside the tube becomes sufficiently large, it will buckle non-axisymmetrically. Once buckled, the tube is very flexible leading to strong fluid-structure interaction. Experiments show that in this buckled state, the elastic tube segment has a propensity to develop large-amplitude self-excited oscillations of great complexity when the flow rate is increased beyond a certain value.

This project aims to further our understanding of some of the mechanisms that can lead to this instability of flow through an elastic-walled tube. The fluid flow will be described by the Navier–Stokes equations, and an appropriate elastic model will be used for the tube wall. Whittaker et al (2010) developed a relatively simple model for small amplitude, long-wavelength, high-frequency oscillations. Work is currently underway on extensions to include shear effects, wall inertia and axial bending. This project will start by working to relax some of the remaining assumptions in the previous model, e.g. adding nonlinear effects and allowing for different cross-sectional shapes. The project will likely focus on developing reduced analytic models (which may need to be solved analytically or numerically) though there is also scope for conducting full-scale numerical simulations.

There is no specific funding allocated to this project. However, some funded studentships are available from the University to well-qualified students. Self-funded students can be considered too.

- High-Frequency Self-Excited Oscillations in a Collapsible-Channel Flow
- , 2003.
- Annual
Review of Fluid Mechanics
**481**, 235. - Biofluid Mechanics in Flexible Tubes
- James B. Grotberg & Oliver E. Jensen, 2004.
- Ann. Rev. Fluid
Mechanics
**36**, 121. - Predicting the Onset of High-Frequency Self-Excited Oscillations in Elastic-Walled Tubes
- , 2010.
- Proceedings of the
Royal Society A
**466**(2124), 3635–3657. - Fluid–Structure Interaction in Internal Physiological Flows
- , 2011.
- Annual
Review of Fluid Mechanics
**43**, 141–162.

Further details of my work in this area can be found on my collapsible tubes research page.