STUDY OF HELICOPTER BLADE FLUTTER

Abstract

This study is to determine the effect of the flutter phenomena on the helicopter blades. Analytically the exciting force should not exceed the damping force when it exceeds the damping force the flutter will happen. Also the inter section point between the damping and the exciting forces specified the critical rotational speed. There is some impendence such as the rigidity of the blade model used which causes possibility of breakdown of the blade because the angle of attack of the blade is already adjusted and has no ability for flapping. But in articulated blade the angle of attack is adjusted to be suitable for various flight conditions. An experimental facility (wind tunnel) was used to determine the relationship between load distribution at various locations along air foil and possibility of flutter at several angles of attack. It is found that after adding the loads at the leading edge it is observed that the center of gravity will moved forward which lead to delay in flutter comparing with case( without load ). Besides that experimentally the results are not accurate. Also we suffer from proper design of airfoil used because it’s heavy and rigid when it’s made from fiber.in addition the airfoil is longer than the test section