Plumes and Fingers on Fluid Interfaces

The formation of unstable plumes and fingering structures at Fluid Interfaces

Degree type


Closing date

25 September 2023



Citizenship requirement

Domestic / International

About the research project

This project is concerned with developing a fundamental understanding of the physics and mathematics of processes that drive the formation of large-scale unstable structures at fluid interfaces.  These can occur wherever two different fluids meet at an interface that is free to deform.  Such situations are encountered in some industrial processes, as well as in a variety of naturally-occurring situations in the Ocean, the Atmosphere and even in Astrophysics.
In recent years, a suite of mathematical and computational techniques has been developed here at the University of Tasmania, to cope with the evolution of large-amplitude structures that form at fluid interfaces [1], [2].  This project will build on this expertise, to develop new methods for some novel applications.  To begin, these methods will be extended to cope with fluid flow through porous media, so as to enable a study of pollutants in groundwater, for example.  The famous Saffman-Taylor instability will be considered, in which a less viscous fluid pushes a more viscous one; it is known that the interface between these two fluids can be unstable, and develop large finger-like structures as time progresses.  These will be analyzed mathematically and computationally, under a variety of different circumstances.  This work will then be extended to allow both the fluid viscosity and the fluid density to vary across the interface, potentially giving rise to new types of instability of relevance to flow through porous media.  It is also intended to extend this work to situations that no longer involve a porous medium, so that the two fluids of different viscosities engage directly; this is anticipated to provide new understanding of the behaviour of melt-water from ice sheets into the Ocean environment.  In this application, a combination of both plume and fingering structures is anticipated to occur, and will provide new insight into the mixing processes that occur in these Antarctic outflows.

[1]  Lawrence K Forbes, Catherine A Browne, Stephen J Walters,  "The Rayleigh–Taylor instability in a porous medium",  SN Applied Sciences (2021) 3:188 |
[2]  Lawrence K Forbes, Ross J Turner, Stephen J Walters,  "An extended Boussinesq theory for interfacial fluid mechanics",  Journal of Engineering Mathematics 133 (1), 10 2 (2022)

Primary Supervisor

Meet Dr Michael Brideson


Applicants will be considered for a Research Training Program (RTP) scholarship or Tasmania Graduate Research Scholarship (TGRS) which, if successful, provides:

  • a living allowance stipend of $31,500 per annum (2023 rate, indexed annually) for 3.5 years
  • a relocation allowance of up to $2,000
  • a tuition fees offset covering the cost of tuition fees for up to four years (domestic applicants only)

If successful, international applicants will receive a University of Tasmania Fees Offset for up to four years.

As part of the application process you may indicate if you do not wish to be considered for scholarship funding.

Other funding opportunities and fees

For further information regarding other scholarships on offer, and the various fees of undertaking a research degree, please visit our Scholarships and fees on research degrees page.


Applicants should review the Higher Degree by Research minimum entry requirements.

Ensure your eligibility for the scholarship round by referring to our Key Dates.

Additional eligibility criteria specific to this project/scholarship:

  • Applicants must be able to undertake the project on-campus

Selection Criteria

The project is competitively assessed and awarded.  Selection is based on academic merit and suitability to the project as determined by the College.

Application process

  1. Select your project, and check that you meet the eligibility and selection criteria, including citizenship;
  2. Contact Dr Michael Brideson to discuss your suitability and the project's requirements; and
  3. In your application:
    • Copy and paste the title of the project from this advertisement into your application. If you don’t correctly do this your application may be rejected.
    • Submit a signed supervisory support form, a CV including contact details of 2 referees and your project research proposal.
  4. Apply prior to 25 September 2023.

Full details of the application process can be found under the 'How to apply' section of the Research Degrees website.

Following the closing date applications will be assessed within the College. Applicants should expect to receive notification of the outcome by email by the advertised outcome date.

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