変形するノズルから流出する噴流

抄録

As a part of study on the diffusion control of jet flow, the purpose of this study is to control the jet diffusion by using the deforming nozzle. The shape of polypropylene nozzle can change from square shape into cruciform one smoothly. The velocity measurement of the jet flow was performed using a hot-wire sensors, by changing the shape of nozzle exit variously. The basic characteristics of the jet flow, such as velocity distributions and half value widths have been obtained. As a result, it has been clarified that the jet width of the deforming nozzle is suppressed in the downstream location from the nozzle exit to the 8 times the characteristic length. And the jet width of the deforming nozzle in xOy'-plane is small, comparing with that in xOz-plane. Moreover it has been also found that the diffusion of the deforming nozzle is same level in both planes in the downstream location more than 10 times of the characteristic length. Furthermore, in the in the downstream location more than 13 times of the characteristic length, in the case of the shape of the nozzle is a square, the diffusion of the jet is suppressed and the jet diffusion in the case of changing the shape of the nozzle continually periodically is promoted.