The study presents evaluation of optical measurements of the air flow field near the fluttering profile NACA0015 with two-degrees of freedom, Mach number of the flutter occurence were M = 0.21 and M = 0.45. Aerodynamic forces (drag and lift components) were evaluated independently on the upper and lower surfaces of the profile. Using the mentioned decomposition, the new information about mechanism of flutter properties was obtained. The forces on the upper and lower surfaces are phase shifted and are partially eliminated as a result of the circulation around the profile. The cycle changes of these forces cause the permanent energy contribution from the airflow to the vibrating system. and Obsahuje seznam literatury
The aim of this contribution is to present a basic survey of publications dealing with the means of vibration suppression in several kinds of self-excitation. The attention is given to passive and active means using parametric excitation. A special attention is given to the latter and the necessary steps for answering important questions are formulated to initiate further investigation and especially application to real systems. and Obsahuje seznam literatury