Understanding effects of flow conditions on wakes of tidal turbines through small scale testing

Title:Understanding effects of flow conditions on wakes of tidal turbines through small scale testing.

Researcher: Khilan Shah

Supervisors: Luke Myers and AbuBakr Bahaj


Over the past decade many countries around the world have committed to reducing carbon emissions. In order to accomplish this there needs to be an increase in the use of renewable energy. Many places around the world including the UK have opportunities to harness the large predictable renewable energy resource available in the form of marine currents.

The tidal turbine industry has significantly grown in recent years with the proven long term deployment of single devices successfully generating electricity. Commercial arrays of multiple devices have been approved and are soon to be installed.

However each tidal site has its own unique flow conditions in terms of bathymetry, flow speed and levels of turbulence. As yet there has not been enough large scale test performed at these tidal sites to fully understand how these different flow features affect both device performance and wakes. Understanding how the wakes behave is important in the planning of large arrays of multiple devices as downstream devices will be operating in the wakes of those upstream.

This research aims to help address this lack of knowledge by the use of small scale flume testing of single and multiple devices modelled by porous disks. The use of porous disks offers a good approximation of the far wake of a full scale tidal turbine device in small scale experiments. The research will investigate how different flow conditions such as depth and turbulence levels affect the flow around devices and what implications this has for large arrays.


Shah, K., Myers, L. E. and Bahaj, A. S. (2014) Scale experimental modelling of a multiple row tidal array, In Proceedings of the 2nd Asian Wave and Tidal Energy Conference, Tokyo, Japan, 28 July – 1 August 2014.

Myers, L., Shah, K. and Galloway, P. (2013) Design, commissioning and performance of a device to vary the turbulence in a recirculating flume, In Proceedings of the 10th European Wave and Tidal Energy Conference, Aalborg, Denmark, 2 – 5 September 2013.



Fig 1 Shah

Experimental modelling of tidal turbine devices and arrays using porous disks in a flume.

Shah Fig 2

Flow velocity map of 10 disk array

Posted in February, 2015