THE 3-DIMENSIONAL TURBULENT BOUNDARY-LAYER FLOW AROUND BRIDGE PIERS

The three-dimensional skewed flow around circular cylinders placed on smooth, rough rigid and rough mobile (with scour hole) beds was analyz ed in terms of the theories of the three-dimensional turbulent boundar y layer (3DTBL). Performance of various cross-flow and near-wall simil arity models was evaluated and the effects of roughness and scour hole were discerned. Perry and Joubert's model gave best results among cro ss-flow models. All near-wall models gave nearly identical results bec ause of the small cross-flow but none gave good results, However, some indications of the near-wall similarity were found. The polar plots w ere found to be helpful in interpreting the cross-flow behavior, espec ially the effects of roughness and scour hole on it.