Flutter analysis of cascades using an Euler/Navier-Stokes solution-adaptive approach

In this study, cascade nutter analyses for inviscid and viscous flows are p resented. In the present time-domain approach, the structural model equatio ns for each blade as a typical section having plunging and pitching degrees of freedom are integrated in time by the explicit four-stage Runge-Kutta s cheme, A solution-adaptive finite volume method with globally/rigid-deforma ble dynamic mesh treatments is introduced to solve the two-dimensional Eule r/Navier-Stokes equations. For viscous non's, the Boldwin-Lomax turbulence model and two transition formulations are adopted. By comparing with the re lated data in two inviscid transonic-cascade-nutter problems, the reliabili ty and suitability of the present approach are confirmed. From the time his tories of blade displacements and total energy in transonic;flutter calcula tions, it is observed that the viscous effect has a damping influence on th e aeroelastic behavior. The instantaneous meshes and vorticity contours cle arly indicate the shack/boundary-layer interaction, large vortex structure, and big plunging motion in the transonic nutter, subsonic stall nutter, an d supersonic bending nutter respectively. By using the fast Fourier transfo rmation and modal identification techniques, the aeroelastic behaviors in t he inviscid transonic and viscous transonic, subsonic stall, and supersonic bending nutter problems are further investigated.