Meventus, Stena Reneeable, Oberga Vind AB, Vestas|| Sponsors:
Swedish Wind Power Technology Centre (SWPTC) and Energimyndigheten
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The aim is to learn more about the effects of clearing forest around a wind turbine to increase production and minimize loads. The study will cover both the effect of large clearings and provide recommendations for the dimensioning of clearings in order to maximize production and minimize the maintenance costs and fatigue loads on turbines
We expect to provide knowledge on the effects of key-hole cuts and clearings in forests around windfarms, including the effects on turbulence, fatigue loads on turbines and energy production.
Further, we expect to provide general recommendations on how and where to clear forest around a wind farm, and how key-hole cuts should be designed to minimize the maintenance costs and fatigue loads on turbines.
Measurements will be performed at test site C made available by Stena Renewables. At the test site, which will include a wind farm, scanning LIDAR measurements will be performed by Meventus before and after the tree felling. Chalmers will carry out advanced CFD simulations of the site coupled to energy production and load predictions. Simuiation of the windfarm of Oberga Vind AB will also be performed. Vestas will contribute with their expertise.
WP 1: CFD Simulations Wind field simulations will be performed in two stages. In the first stage (Stage I), test case C will be simulated, before and after tree felling, making use of the measurements to verify the models. The second phase aims to find the optimal size and shape of clearings and key whole cuts by simulating hypothetical cases.
I Simulations, using SOWFA, of the wind flow field will be performed before and after tree felling at test site C. The predicted flow field before and after the clearing around the wind farm will be compared with the LIDAR measurements made in WP2. The predicted fatigue forces, obtained by FAST, with and without clearing will be evaluated and compared. SCADA data from the turbines collected in WP2 will also be used as a source for verification of the models and to evaluate the production effects.
Simulations of the windpower stations of Oberga Vind AB will be carried out before and after tree felling. The predicted energy production and loads will be compared with existing SCADA data.
II Simulations of hypothetical clearings with different sizes and shapes will be performed with SOWFA. The predicted fatigue forces (obtained by FAST) with and without clearing will be evaluated and compared. The aim is to find recommendations on how large clearings should be in order to make a balance between high production and minimal maintenance cost.
WP 2: Experiments A test site (denoted test site C) in forested terrain with an existing windfarm and planned tree felling will be made available for measurements and modelling by Stena Renewables. A wind measurement campaign with a scanning LIDAR will be performed before (spring 2018) and after the tree felling (spring 2019). The measurement campaign will be designed to be used as verification of the wind flow simulations. SCADA data from the turbines before and after the forest clearing will also be collected and analysed to see the effects on production and fatigue loads.
Since open-source software (SOWFA and FAST) is used in the project, the simulations tools will be made available for the Swedish Windpower industry and the Swedish universities.
This page, Fatigue Loads in Forest Regions, should be part of a frames system at www.tfd.chalmers.se/~lada/projects/proind.html