直線開水路流れの2次流について

Abstract

It is well known that the secondary flow can be observed in a straight open channel, however, it is elusive to be detected because of its small magnitude and unstableness. The secondary flow is investigated experimentally or numerically by many researchers. In this paper vortex motions induced by the secondary flow are classified on the basis of its cause; velocity gap, flow boundary and bed-generated turbulence, and discussed by using the results of 3-D LDA measurements, flow visualization in a transverse cross section and an algebraic stress model (Naot-Rodi model). It is found that there are some difference between the time-mean secondary flow obtained by LDA and N-R model and the instanteneous secondary flow by the flow visualization.