Control of Jet Diffusion by Fluttering Fins

As a part of the investigation on the control of jet diffusion, the flow visualization of jet has been conducted. The jet issues from the pipe exit where the soft fins made of an artificial cellulose are attached. By using the experimental results from the PIV method, the jet width has been obtained. Moreover, the wavelet multi-resolution analysis has been carried out, by using the images from the LIF methods. As a result, it has been found that the fluttering fin affected the jet diffusion largely and this effect appeared remarkably in case of a long fluttering fin. Furthermore, the difference of the flow structure between the jet flow with and without fluttering fins is recognized from the results of the wavelet multi-resolution analysis.