Ultrasonic gasmeter for domestic purposes are already available. For these kind of instruments the repeatability and accuracy of the flowmeter output are dependent on the fluid properties, the production tolerances and the choice of materials. A significant influence on the measurement arises from dust which affects the transducers, the reflection and distribution of the ultrasound, and the gas flow in the tube. Presently a filter is used to minimize these effects, but the additional pressure drop is undesirable.
The aim of this project is to overcome these difficulties and to improve ultrasonic gas flow meters in generic form. To this end, physical and computational modelling is being undertaken to study (i) the propagation of sound through a moving medium, (ii) the sensitivity of flow measurements to dust transport and dust deposition in the measuring tube and (iii) the sensitivity of flow measurements to gas properties. These theoretical investigations will help to design and construct some ultrasonic flow meter prototypes with different geometries. These meters will then be subjected to extensive laboratory tests (calibration, measurement of the dependence for different gases, measurements at different dust concentrations, determination of velocity profiles, etc.). The final instruments are intended to work without filters, showing the same reliability and precision of existing domestic gas meters. These new meters shall fulfill the OIML-specifications.
Funding SchemeCSC - Cost-sharing contracts
LE11 3GR Loughborough - Leicestershire
MK45 4DT Cranfield