The properties of two-dimensional Coanda nozzle jet passed a circular cylinder with symmetric / unsymmetric nozzle exit are investigated experimentally focusing on several stable flow patterns with and without disturbance acted at the nozzle exit.
The flow pattern formed without disturbance is deformed by some disturbance imposed at the nozzle exit and eventually settles in as another stable one. From this fact, we conclude that the solution of the Navier-Stokes equation is not unique, when Coanda effect is dominant.
It is observed that, when the flow is disturbed, the development of a single jet along the axial direction of the jet is accomplished farther from the center of the cylinder than un-disturbed case. In the case of symmetric nozzle exit, the rate of increase of mass entrainment along the axial direction of the jet is increased with downstream whereas it is decreased in the un-disturbed case.
The direction of flows can be determined by a momentum ratio per unit width ejected at two nozzle exit.
