Investıgatıon of Effects of Bırd Strıke on A Rotary-Wıng Aırcraft

Abstract

Bird strike incidents have been important issue since begining of aviation, and importance of bird strikes increase day by day. Number of bird strike incident are going to continue increasing because of developing aviation industry and increasing air traffic. Airspeed of rotary wing aircraft changes with pitch angle. Therefore, effect of bird strikes at different airspeeds changes with not only airspeed but also impact angle. Within the scope of this study, effect of bird strike on a rotary wing aircraft was investigated and it is aimed to bring an example study to the literature of our country. After history of bird strike was mentioned chronologically, information was given about effects of bird strike incident to general aviation and helicopters which are rotary wing aircraft. Also, one helicopter crash occured because of bird strike was mentioned. After giving information about applying forces on flying helicopter and explaining how helicopters fly, impact scenarios were determined for anayses. Finite element methods were explained and compared with each other for bird strike analysis. After defining a geometry, dimensions and density of bird, analyses were done using each bird geometry using Lagrangian, SPH and ALE methods according to speed and mass given in literature. Results were evaluated and the optimal finite element method–bird shape combination was determined. Strike analyses were done using determined finite element method – bird shape combination in accordance with data of previous experimental bird strike study before analysis setup was verified. After defining impact surface, impact speed and strike angle, final analyses were done at 80, 85, 102, 110 ve 120 knots impact speeds with excluding effect of strike angle and including effect of stike anglei respectively. Finaly, effects of bird strike on a rotary-wing aircraft were investigated.