Fully Developed Turbulent Flows through Rectangular Ducts with One Roughened Wall

Two ducts, one with a long-side rough wall and the other with a short-side rough wall, have been used. The distributions of the mean velocities and turbulent stresses over a whole cross section in the fully developed region were measured by hot-wire anemometry. The secondary flow distributions in both the rough ducts were remarkably different from those in the smooth-walled duct