NPL and Imperial College London's Institute of Shock Physics (ISP) are working on a Knowledge Transfer Secondment project funded by EPSRC.
High speed pressure sensors are used to monitor rapid changes in pressure, such as those found in turbines and internal combustion engines. There is currently a requirement to ensure that these dynamic measurements are giving true real-time pressure values, so NPL is developing a source of pressure steps with the pressure change across the step traceable to the SI. Such pressure pulses can be produced using a shock tube where the rapid bursting of a metal diaphragm, exposed to high pressure on one side, generates a shock wave which provides a well-defined pressure step whose height can be calculated from measurements readily traceable to the SI.
These effects are being investigated in collaboration with the ISP who provide experience in the production of the diaphragms along with diagnostic equipment (high-speed cameras, velocity probes, deformation metrology) and help with the analysis of the data. The objective of the work is to be able to produce pressure pulses suitable for the calibration of high speed pressure sensors using bursting diaphragms in a shock tube.
For more information, please contact Ian Robinson