Evaluation of Flutter Analyses in the Context of New Concepts of Preliminary Aircraft Design

Kurzfassung

The process chain of the aeroelasic flutter analysis for new aircraft configurations is presented in the context of the preliminary aircraft design and optimisation program PrADO of the IFL. Therefore a recalculated Fairchild Dornier 728JET is used as an example. The different software modules used in this process chain are described together with the models, which are needed for the computation: PrADO is used to calculate a fully converged aircraft design by an iterative process. As eigen frequencies and eigen modes of the aircraft structure are used by flutter analysis, a structural model for modal analyses with MSC.NASTRAN is generated by a PrADO sub module and transformed into the NASTRAN bulkdata format. With geometry information of PrADO database a ZAERO model is created to perform automated evaluation of flutter proneness. The results of the flutter analysis of the FD 728JET, performed at Fairchild Dornier, are compared to the results of the PrADO design. The differences between both are detailed. Further a modified PrADO 728JET with winglets is compared to the baseline design.