Tidal Turbine Blade Shape Optimisation
Multi-objective Optimisation Challenge
Tidal Turbine Blade Optimisation
This is a great example of a multi-objective optimisation problem that has successfully employed Blackfish's in-house optimisation and blade element codes to optimise blade designs.
Blackfish have carried out blade optimsation for multiple tidal turbines, working with the turbine developer to understand their definition of "optimal" and the constraints to work within.
In these examples the optimal design was often one that produced the peak hydrodynamic efficiency at the operating tip speed ratio, while not exceeding the structural integrity of the blade.
Iterations could be undertaken with different hydrofoil profiles to understand both their performance and structural impacts. In most cases a full search of the design space and an optimal design could be generated in less than 30 minutes of computational time.
High Level Overview
The optimiser had control over chord, twist and thickness distributions to generate blade shapes and test their performance using Blackfish's in-house blade element code. The performance could then be given a score to find the optimal blade.
This sort of problem is perfect for the differential optimisation routine used as there is a broad design space with multiple contours of performance, where it is likely to achieve peak performance you will want to operate close to what is structurally allowable.
In some cases where this optimiser has been used for tidal turbine blades additional limitations have been placed on the blade chord (manufacturable limitations), the peak torque (gearbox limitations) and the peak thrust (other structural limitations).