Abstract
In this paper, to clarify the random switching mechanism of an attached jet, characteristics of velocity fluctuations of the attached jet are investigated experimentally by using a large scale fluidic model. The relation between turbulence and random switching is made clear.
The turbulence intensities of an attached jet and a free jet were measured. For the attached jet, the power spectrums and the probability densities of velocity fluctuations were also measured.
Based on the experimental results, velocity fluctuations near the half width of the velocity profile of the attached jet, which is equilibrium with the control flow, are considered as stationary normal random oscillations and the random switching model is given.
Values of model parameters are estimated from the experimental results and the distribution parameters of switching delays are calculated. This calculation agrees with the experimental results of switching delays in the random switching process. Thus the validity of the random swishing model based on the randomness of velocity fluctuations is confirmed.
