A sound way to ensure sustainable energy

A new company in the process of being spun out of academia is to focus on condition monitoring by acoustic emission. In last year's MTEC preview, we reported on the success of the Brunel Centre for Manufacturing Metrology in devising a system to monitor the condition of the main bearings of the London Eye. This, year, we can report that the team is setting up a spinoff company, Advanced Acoustic Emission Systems and plans to extend its business to monitoring blade pitch bearings in wind turbines and other items. Professor Barry Jones explained to Eureka that the need has arisen because of the government's target to generate 10% of the UK's energy from renewable resources by 2010. Much of this is likely to be from wind power, some of which is likely to be offshore, and relatively difficult to access for maintenance. While main shaft bearings are precision built and run continuously, blade pitch bearings, which he describes as being relatively "Roughly made", are used only occasionally, but have to work when required if serious damage is not to be incurred in storm conditions. The bearings are typically 1m or more across in large turbines. Professor Jones's team has been working with NEG Micon, the world leading Danish manufacturer of a large proportion of the world's wind turbines. Professor Jones told Eureka, "Indications are that we can get very useful information with benefit to long term preventative maintenance, using a new parameter that we have developed and patented." While understandably cautious about giving away exactly what this parameter is, we can reveal that it provides accurate information unrelated to detected sound intensity, and, "Seems likely to arise from actual failure mechanisms." Professor Jones believes that the new technique is applicable to the condition monitoring of all bearings, and may, in the case of the blade pitch bearings, also be used to assess them prior to installation and "Obtain some quality assurance." The team has continued its work with BAe Systems, looking at ways to monitor composite patches, used to repair composite constructions in aircraft following damage by bird strike or other mishaps. The team is doing modelling work and looking at suitable parameters. Professor Jones says they are also in discussions with London Underground about coming up with new, automated condition monitoring systems. At present, he considers many of the monitoring systems on the Tube to belong to the, "Men riding bicycles along the track to look for problems era." MTEC stand no. TTZ8 Professor Barry Jones web page email Professor Barry Jones Pointers * Acoustic emission may be used to detect the beginnings of damage in large, low speed bearings, long before it might cause failure * A new parameter has been developed which produces accurate information not dependent on detected sound amplitude * The technique may also be suitable for quality assurance and has a variety of other potential condition monitoring uses