Aeroelastic analysis of helicopter rotor blades on deformable chimera grids

Abstract

Aeroelastic Reynolds-averaged Navier‐Stokes and Euler computations are presented for an articulated model rotor in hover and forward flight. Comparative rigid-blade simulations are carried out to assess the effects of blade dynamics and elasticity on the numerical results. The INROT flow solver operates on deformable structured overset grids and can be tightly coupled with a finite element model of the rotor blade structure (DYNROT) based on Timoshenko beam theory. The order of time accuracy of fluid and structure modules is maintained in the overall analysis by an appropriate staggered coupling scheme. At the investigated thrust setting, global hover performance values computed by the coupled fully turbulent Navier‐Stokes analysis agree fairly well with available experimental data. In forward flight, the aeroelastic results are in much better agreement with the measurements than those obtained from rigid-blade simulations with prescribed articulation. Apart from superior rotor power predicition, the local pitching moment coefficients computed by the viscous analysis are found to correlate better with wind-tunnel data than the corresponding Euler output.