Monday, 6 July 2015
FlySafe will assess flywheel failure modes
Ricardo, in collaboration with various industrial and academic partners, has delivered a flywheel safety test environment to develop next-generation flywheel energy storage systems.
As a result, the FlySafe project has been established to investigate potential failure mechanisms and behaviours of high-speed flywheel systems.
Operating a high rotational speeds, these systems offer a practical and potentially cost-effective mechanical means of saving fuel and reducing carbon emissions through the mechanical storage and reuse of energy in applications such as regenerative braking.
The FlySafe research aims to provide best-practice design guidelines for the safety containment systems of high speed flywheels, appropriate for commercial mass market deployment of these systems. A key output of the project in this respect will be a proposed BSI flywheel safety standard.
The research will use a new test environment at the University of Brighton, UK, to gain an understanding of the rate of energy release, enabling industry to design safety containment systems that are compact, light-weight and low cost, while effective in providing flywheel safety.
The test environment, now been completed, has been developed by the FlySafe project and installed at the Centre for Automotive Engineering, Brighton. It is believed to be the first and most advanced of its type in the world.
The unit is capable of testing flywheels spinning at up to 60,000 rev/min in a vacuum. In addition to providing for non-destructive testing, it incorporates imaging and sensor technology to investigate the behaviour of flywheels when one or more engineering defects might cause to the flywheel to fail at high-speed through the incorporation of a range of engineered defects.
Video is acquired with a high-speed system recording at 20,000 images per second with the flywheel illuminated by a high-intensity pulsed laser synchronised to the camera. At this high frame rate the camera can record approximately just two seconds of video, so accurate synchronisation of the recording with the failure event is critical.
The University of Brighton has developed a custom data acquisition system monitoring a number of sensors to enable this. These include accelerometers, strain, pressure, distance and temperature measurements within the flywheel enclosure and allowing to trigger the camera on the occurrence of specific conditions which might be expected to lead to failure.
Such failure conditions might include, for example, a sudden expansion of the flywheel due to the onset of delamination or fragmentation, loss of vacuum pressure, or loss of speed.
A key objective of the FlySafe research is to gain an understanding of the rate of energy release, enabling industry to design safety containment systems that are compact, light-weight and low cost, while effective in providing flywheel safety.
The FlySafe project, supported by Innovate UK, is a collaboration between Ricardo, the University of Brighton, Imperial College London and three leading UK based high-speed flywheel energy storage technology developers – Torotrak Group and GKN Hybrid Power and Ricardo.
The project builds upon high-speed imaging techniques that were originally developed as part of the University of Brighton’s extensive research in visualising fuel sprays and combustion events in engines.
As such, the project is opening a new area of interdisciplinary research, combining the University’s existing optical techniques expertise with those of materials engineering researchers at Imperial College London. This new collaboration will provide fundamental understanding of the failure processes in composite flywheels.