olefud wrote:While vortices are often wasteful, when provoked in the boundary layer they are useful to maintain boundary layer attachment. As the shear between laminar layers across the velocity profile increases, vortices formed between layers can function as “rollers” that decrease shear friction within the boundary layer.
Wake vortices are just a form of turbulence. And since they are an energy transfer to the airflow, they basically represent a loss of energy. Some of that energy can be recovered if the vortex flow is put to use assisting other flows, such as the vortex generators on front wing end plates, or gurney flaps on wing trailing edges or outlet duct edges. In reality, all of these vortex generating devices are just an inefficient band-aid fix to a poor flow condition in some other aero device.
