Influence of Fluid Viscosity and Compressibility on Nonlinearities in Generalized Aerodynamic Forces for T-Tail Flutter

The numerical assessment of T-tail flutter requires a nonlinear description the structural deformations when unsteady aerodynamic forces comprise terms from lifting surface roll motion. For linear flutter, deformation vertical tail plane (VTP) out-of-plane bending results in spurious stiffening proportional to steady lift forces, which is corrected by incorporating second-order equations While effect these components on stiffness VTP mode shape known literature, their impact coupling involved has not been studied so far, especially regarding amplitude-dependent characteristics. This term affects targeting common analysis, as well study dynamic aeroelastic stability phenomena, e.g., Limit Cycle Oscillations (LCOs). As LCOs might occur below boundary, fundamental knowledge about and nonlinearities occurring dynamical system essential. paper gives an insight into for representative usually encountered mechanisms using CFD approach time domain. It further outlines geometrically nonlinearities. this, horizontal (HTP) considered isolated form exclude interference effects studies subjected rigid body yaw motion approximation shapes. complexity aerodynamics increased successively subsonic inviscid flow transonic viscous flow. At Mach number, distinct nonlinearity damping HTP shown. Geometric result almost entire cancellation increase nonlinearity. offset with respect results, but do alter observed nonlinearities, geometric amplified reduced considerably. Here, reduces well, does cancel it.