PDF《alluvial channel》

0 and L00 is shown in Figure

1 in which L0 is the characteristic length where the flow have direct contact with the bed, and L00 is the characteristic length of the separation zone behind the bed form, where because of the eddy formation, there is an obvious reduction of direct contact area between the flow and the bed that was realized by Chien and Wan [1999]. If we divide both sides of equation (5) by L, we obtained the energy slope as follows S ? hf L ? h0 f L0 L0 L ? h00 f L00 L00 L ? S0 L0 L ? S00 L00 L ?6? Equation (6) provides a physical basis to Engelund'

s ap- proach (equation (4)) and probably explains why his method performs best among the existing models as reported by Bennett [1995]. However, equation (6) implies that there is an implicit assumption suc........