Flutter Analysis Based on the New Numerical Model IAR-99 HAWK Empty Equipped Configuration Aircraft

After creating a new Finite Elements Model (FEM) of the aircraft IAR-99 HAWK using special elements, the team decided to validate the results by performing a free-free vibrations analysis on this model. In this presentation we have described the finite elements used and their peculiarities, the finite elements model obtained for the aircraft IAR-99 HAWK and the results of the free-free vibrations analysis obtained in the empty equipped configuration. The results of the theoretical free-free vibrations obtained for the IAR-99 HAWK in the empty equipped configuration are presented and compared to those obtained from ground tests, thus confirming the accuracy of the new Finite Element Model (FEM). The aerodynamic idealization of the IAR-99 aircraft was made using the DLM method for subsonic flow, also considering the load-bearing surface/fuselage interference and aims to determine the generalized aerodynamic forces that occur on one mode of vibration due to the influence of another mode of vibration. The flutter calculation for the IAR-99 HAWK empty equipped configuration aircraft was made using the p-K methodology presented in the MSC.Nastran program, using the vibration modes obtained on the basis of the new finite element model and the matrix of generalized aerodynamic forces in subsonic flow.