抄録
In this paper, as the first necessary step towards practical application, the effects of sound on the reattachment of water jets to a short flat wall are experimentally investigated on the basis of the fundamental characteristics of two-dimensional water jets sensitive to sound and are compared with those of the case of a curved wall shown in a previous paper. In addition, the transient response of the test device with a receiver located in the jets, is examined by using sound as a control input in order to discuss the possibility of applying the phenomena of the reattached jets to fluidics. Besides, the reattachment phenomena of water jets affected by sound are considered from the statistical inference of the response time.
The following facts are confirmed:
1) A short flat wall gives fundamentally three phenomena of reattached jets sensitive to sound as well as a curved wall does.
Contrary to the case of the curved wall, however, even a separated jet is affected strongly by the flat wall and a reattached jet doesn't run on the wall because the jet locks on to the termination of the wall.
2) The dynamic behaviour of a reattached jet affected by sound are related to the formation of low pressure bubble region, the irregularity of fluctuations in the jets, and the stability of reattachment.
Especially, the process that a reattached jet separates from the short flat wall by sound signal and changes into a separated jet, is random.
