The application of TLM to the modelling of airborne ultrasonics

The work described is a part of extensive programme of research into the use of ultrasonic sensors in advanced manufacturing that has been carried out at Nottingham University since 1983. The goal of the programme is the development of a sensor for industrial application which can measure the range in two dimensions of objects within the field of view for both short range (up to 1 mm) and medium range (up to 5 mm). The work involved investigating the TLM modelling technique as a means of simulating the behaviour of ultrasound in air which include testing specific transducer/processing arrangements, feasibility studies of ultrasonic inspection set ups and modelling diffraction or reflection by objects in two dimensions up to far field range. The TLM modelling system used to model sound propagation and its interaction with solid objects in two dimension have been set up on the SUN-SPARC workstation