Sean Mulligan

Project Title: Investigation of Tangential Velocity Vectors in Free Water Vortices as Applied to Hydroelectric Energy Extraction

Student Name: Sean Mulligan

Supervisor: John Casserly & Dr Richard Sherlock

Funding Body: Institute of Technology Sligo Presidents Bursary Awards


Renewable energy is an integral part of Ireland’s climate change strategy with the purpose of delivering a competitive, all-island energy market. Coinciding with this, the report “Small Scale Hydro Electric Potential of Ireland” indicates that there is an abundance of low-head sites around the country with the potential to contribute considerable energy in the micro hydropower sector, if technologies to exploit this potential can be developed.

Pioneers worldwide have recently begun using the water vortex or whirlpool type structure as an alternative means of generating renewable energy from rivers. The method has the foreseen advantage of operating more efficiently for low heads which are abundant in typical river topology.

The system works by encouraging water vortex formation in a structure placed over a vertical fall on a river. The rotational energy of this vortex is then captured by placing an impellor into the core which spins an electrical generator.

Like any young technology, the system always poses the questions “How efficient can it be?” “How does it offer advantages over conventional technologies?” “How do I design one for a particular location?”. Many of these questions still remain unanswered which are limiting the further development and integration of this technology into the renewable energy market.

This research project sets out to answer these questions by contributing new scientific material on the plant based on analysing velocities of water flow, using Particle Image Velocimetry, in the vicinity of the impellor.  The velocity of flow is directly related to how much energy can be extracted, therefore being the key tool for optimisation.

Publications/Conferences attended:

  • Presentation for the finals of the Innovative Student of the Year Award at The Engineers Ireland Head Quarters in June 2010.
  • Mulligan. S.; Hull, P. (2011). The Design and Optimisation of a Water Vortex Hydropower Plant Environ 2011 Colloquium
  • Presented research poster at the first Sligo Institute of Technology Research Showcase
  • Presented research poster at the Athlone Institute of Technology Research Showcase

Water Vortex Formation in Physical Model