How to calculate aerodynamic losses?

Whiffle uses a physical, first-principle-based weather and wind farm simulation model, and therefore we cannot readily separate the impact of wake and blockage effects on the modelled cumulative production of the wind farm.

However, it is possible to determine total aerodynamic losses by running two simulations: a standard simulation, in which the turbines execute a thrust force on the flow, and an additional simulation using thrust-free turbines, in which the turbines impose zero drag on the wind flow. Thus, thrust-free turbines are “virtual turbines”, which produce power without affecting the wind flow.

Total aerodynamic losses are then calculated by simply subtracting the energy produced by the standard turbines from the energy produced by the thrustless turbines. This is represented by the following equation:

Total aerodynamic losses = Power produced by thrust-free turbines - Power produced by turbines with thrust

Setting up simulations for total aerodynamic losses

Two simulations are needed, which can be executed in random order. One simulation is with thrust and another thrust-free.

First with thrust simulation:

Set up a new simulation. In the Wind farm step, you can toggle the thrust for turbines on and off for each wind farm. Thrust is enabled by default for all turbines in new wind farms, so no additional action is needed.

Second thrust-free simulation:

After submitting the first run, you can use it as a template for the second run by clicking the "Copy & Edit" button on the Simulation overview page.

Ensure all turbines are set to thrust-free by turning off the thrust toggle for each wind farm.

Calculate aerodynamic losses

We provide the Whiffle API Client to easily calculate aerodynamic losses. See our example notebooks for more information.

API client