Aeronautical Development Agency (ADA)
Fighter aircraft typically carry a number of different under-wing external stores such as fuel tanks, bombs and missiles. The geometrical and inertial parameters of these stores have an influence on the flight envelope and the flutter characteristics of the aircraft. An imported aircraft is certified by the OEM for the carriage of certain stores within a specified envelope. However, if the country which has acquired the aircraft decides to integrate a new store, then it has to either approach the OEM to help in the certification process or devise a mechanism to carry out the exercise itself. The former approach has a twofold disadvantage: violation of secrecy and also the prohibitive cost. Hence, it is imperative that an independent approach, along with the local certification authorities, be evolved to achieve the required objective.
Challenge:Determine unsteady air loads due to the structural vibration modes at various altitudes and speeds
Results Validation:“The excellent correlation between FE based flutter analysis and flutter analysis based on GVT data validated the use of this method on the second aircraft, the one with a new store requiring flutter clearance.”