Xi Engineering had previous experience working with the ETP on a separate project involving the Centre for Signal and Image Processing at Strathclyde.
Their core business is to provide noise and vibration solutions to a wide range of industries with a predominant focus on the renewables sector. One issue that came to light in the last 6 months is the problem of tonal noise in a wind turbine tower. The tower is known to have several resonant frequencies corresponding with the main operating modes of the drive- train. Thus if any of these modes are excited by the tower it will result in amplification of vibration and emission of problematic tonal noise.
The ETP funded a consultancy project, in conjunction with Heriot-Watt to investigate the use and viability of Xi’s Advanced Particle Damping (APD) pods to mitigate these vibrations within the frequency band of 100Hz-145Hz. The project looked at exciting a steel plate at the desired frequencies and investigated how much of an improvement the use of APD pods may have in reducing tonal noise and therefore displacement. The results were promising and showed a reduction of up to 15dB with a number of APD pods placed at regular intervals across the steel plate.
Following on from this, there were discussions about using the afore-mentioned project as a baseline and expanding the scope to look at noise mitigation offshore. However, unfortunately this project was not submitted within the constrained time-frame left of KENII. Therefore, any further work was placed on hold. However, this project is still viable and there is now an opportunity to engage with Xi on future studies in KENII. The company have expressed how positive the experience of working with Heriot-Watt has been, specifically in terms of gaining access to testing facilities which they do not currently have.