Suppose a fluid passes from having laminar flow, to having a turbulent flow (like when passing after an object). How do fluid speed and fluid density change after that?
In the case of pipe flow, the velocity remains constant simply through continuity, and the losses are influencing only to pressure. In the open channel flow the velocity depends on up- and downstream conditions, and can therefore even be higher after the object, but also lower if the object causes a hydraulic jump.
In the pipe flow the density is influenced only through the thermal expansion caused by the pressure turning to heat. In the open channel flow the density can change quite a lot if air entrainment occurs. The Turbulence has only indirect influence to density.