Characterisation of a Whirling Arm Erosion Test Rig

Abstract

Leading edge erosion is an issue that is affecting many offshore wind turbines. However it is currently unclear the damage mechanism that is initiating and propagating the erosion. The characterisation work carried out at the test rig in the Energy Technology Centre is providing a greater understanding on the droplet impacts, droplet diameters and droplet trajectories. From this work it has been determined that avoiding operating the test rig at the highest rotational speeds improves the droplet control. The preferable standoff height was investigated as a DNV GL standard stated a minimum height of 200mm. Through work with a high speed camera it was determined that the optimum standoff height was 50mm for the ETC rig, due to the use of shrouds. The characterisation work carried out provides a greater knowledge on the droplet impacts however future work should be carried out to increase the sample size to provide clearer results.