Abstract
As a first step of the study on the diffusion control and the direction control of the jet, the basic characteristics of the jet flows, issuing from the pentagonal duct and the circular pipe, were investigated experimentally. The velocity distributions of the jet flow have been investigated using the hot wire sensor and the CTA system. By using the velocity distribution, the velocity decays, the half value widths of the jet and the turbulent intensities have been obtained. As a result, it has been found that there exists the difference of the flow structure between the pentagonal jet and the circular one.
