An Experimental Evaluation on the Performance of High Lifting Rudder under Coanda Effect

초록

It is already known that a flapped rudder equipped with a water jet blowing system can produce higher lift than an ordi-nary one by increasing circulation and delaying stall at large angles of attack and named the Coanda effect (Lachmann 1961, Ahn 2003). In the present study, based on the results accumulated in the previous researches, a model of the rudder device was manufactured and mounted on a model ship to evaluate the Coanda effect on the rudder performance through various tests including free-running tests. During the tests, hydrodynamic forces acting on the Coanda rudder system were measured and compared to those acting on a conven-tional rudder. It is found that the new rudder system is effec-tive in improving the maneuverability of the tested ship