ULTRASONIC TOMOGRAPHIC IMAGING OF AIR FLOW IN PIPES USING AN ELECTROSTATIC TRANSDUCER ARRAY

摘要

Ultrasonic tomographic imaging of gas properties has received little attention, mainly due to a lack of suitable transducers. In this work, a circular array of prototype divergent electrostatic ultrasonic transducers was incorporated into a 100mm diameter test pipe through which airflows of up to 18m/s could be achieved. A bluff body was placed upstream of the transducer array, and cross sectional images of the resulting disturbances at different flow rates were reconstructed using a tomographic filtered back-projection algorithm, based on a fan-beam geometry. The airflow through the array was also modelled using the computational fluid dynamics software package FLOTRAN~R.