Abstract
In order to study on the jet diffusion control, the jet flow issuing from the circular pipe with fluttering fins has been investigated. It has been already recognized from previous studies that the jet diffusion was promoted by attaching fins to the circular pipe and there exists more effective fin length to the jet diffusion. In this paper, the turbulent properties were investigated from the velocity information obtained by the PIV method. This experiment has been carried out in the cases without fins and with fins having the length L/d=1.5 and 2.5. As a result, it has been found that the turbulent intensity is supplied by the fin vibration and a large fluctuating component appears with the increase of the fin length. Moreover, from the results of the auto-correlation, it has been clarified that the turbulent structure contained in the jet flow is destroyed by attaching fins.
