抄録
PIV measurement needs tracer. Generally, solid particle is used as tracer. Solid tracer, however, tends to accumulate on the gap located at wall. It might cause the machine trouble if actual machine was used for the measurement. In this study microbubble is proposed as PIV tracer. In order to investigate whether microbubble is effective as tracer, loci of both microbubble and solid particle tracers are calculated and then compared. Results show both loci are coincides each other. Next, mean velocity distribution of turbulent flow over a backward-facing step is measured by PIV using microbubble and solid particle as tracer. Results show both distribution are well coincide. It can be said that microbubble is available as tracer for PIV measurement of time averaged velocity field.
