Abstract
Turbulence measurements in open-channel flows with a horizontally dead zone were conducted with a two-component LDA system. The aspect ratio(=streamwise length/spanwise length) is changed to 3, 5 and 10. In the case of the aspect ratio of 3, the strength of the rotation of the vortices is large in compared with other cases. In the case of the aspect ratio of 5, the mass exchange is small, however, the momentum exchange is larger than the other case. In the case of the aspect ratio is 10, the reattachment can be seen. The reattachment length is about 5 times of the spanwise length of the dead zone. A new eddy model in open-channel flows with a horizontally dead zone is suggested.
