An experimental study on flow around two-dimensional models with reference to bed from porpagation

An experimental study on the flow around wavy models has been made. All of the models has two crests and two-dimensional profile. It is found that the flow instability around the models depends on the Reynolds number R_∞=U_∞ h⁄υ, where U_∞ is the free stream velocity, h the model height and υ the kinematic viscosity of the fluids, and the steepness S=h⁄λ, where λ is the model wave length, but the flow separation depends on the steepness only. Also, found are that on the surface of the models there appear Taylor-Görtler type vortices once the Reynolds number exceeds the critical value and that the form of the vortices is deformed depending on the Reynolds number and the model profile. On the basis of the present experiment, it is suggested that the intensity and scale of the separation eddy are decisive factors for bed form propagation.