A three-dimensional numerical model of a horizontal axis, energy extracting turbine : an implementation on a parallel computing system

In the last decade, there has been a resurgence of interest in tidal power as a renewable, and environmentally friendly source of electricity. Scotland is well placed in this regard, as the currents in the surrounding seas are primarily tidal; that is to say, driven by lunar and solar tides. Investigations into tidal streams as an energy source, their viability in particular locales, the efficient organisation of marine turbine farms, and most importantly, the effect of such farms on the environment, demand the use of computational fluid dynamics for effective modelling. They also require a turbine model sophisticated enough to generate realistic power output and wakes for a variety of flow conditions, yet simple enough to simulate a number of turbines on modest computing resources. What is presented here then, is the justification for such a model, the development and deployment of it during my PhD, and my validation of the model in a variety of environments

Turbulence characteristics in offshore wind farms from LES simulations of Lillgrund wind farm

AbstractThe effect of wind turbine wakes in large offshore wind energy arrays can be a substantial factor in affecting the performance of turbines inside the array. Turbulent mixing plays a key role in the wake recovery, having a significant effect on the length over which the wake is strong enough to affect the performance of other turbines significantly. We highlight how turbulence affects wind turbine wakes using results from LES simulations of Lillgrund offshore wind farm in the context of SCADA data selected to mirror the wind conditions simulated. The analysis here concentrated on temporal spectra of wind velocities measured by the turbine's nacelle anemometer and calculated at the turbine locations in the computational model. The effect of the wind turbine rotor on the downstream flow is quantified by analysing the change in spectral features of turbines within the wind farm compared to turbines at the side of the farm exposed to the wind