Some specifics of modeling an aircraft aeroelasticity in transonic wind tunnel
Design, construction and manufacturing of flying vehicles
National Research Center "Zhukovsky Institut", 1, Zhukovsky str, Zhukovsky, Moscow Region, 140180, Russia
The article considers specifics of modeling the phenomena of the dynamic aeroelasticity, such as flutter and bugging, on dynamically congruent models in the wind tunnels (WT) in transonic range of Mach numbers.
The goal of the research is developing recommendations on similarity criteria selection for modeling the phenomena of aeroelasticity in the transonic mode by additive technologies.
The major stages of this work are analysis of existing structures of transonic aeroelastic models by weight, stiffness and strength characteristics, and comparative analysis of model materials’ specific stiffness and strength characteristics.
The article gives recommendations for the similarity criteria selection while design, manufacture and testing of dynamically similar models (DSM) in transonic WT. Implementation of the synthesized criterions will allow obtaining the reliable results of the experiment and successful transferring to the full-scale design.
It was shown, that the major problem is caused by the fulfillment of the mass similarity condition – the Newton’s criterion. This problem is stipulated by models’ structure overweighting. The article gives examples of overweighting effect on the flutter critical speed.
The design features of the main types of transonic DSMs force diagrams were considered. The effect of the main strain load carrying elements’ cross sections shapes of DSMs on DSM’s weight effectiveness was considered as well.
A comparative analysis of the specific stiffness and strength characteristics of homogeneous materials (metals), thermoplastics and isotropic composite materials was performed. This analysis results allowed obtain estimations of weight efficiency when used in DSM designs.
The article presents also the prospective directions for weight reduction of models of beam and plate scheme.
Keywords:aeroelasticity, dynamically scaled model, additive technology, similarity criteria, aerodynamic experiment, composite materials
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