A tight two-way fluid-structure coupling for aeroelastic computations in the time domain

A three-dimensional implicit finite element Euler/Navier-Stokes solver based on the Arbitrary Lagrangian-Eulerian formulation has been developed for fluid-structure interactions, moving and deforming bodies, and aeroelastic calculations. The flow solver is complemented by a built-in moving grid algorithm which allows the computational grid for the fluid to move simultaneously with the moving body, without the need for global mesh regeneration and solution interpolation. The flow solver is coupled to a stress solver in a tight fashion at each time step, although both solvers exist independently and are used as black boxes. The aerodynamic loads and the structural displacements are transferred between the two solvers in a conservative fashion using the concept of a virtual grid, which guarantees the conservative transfer of both the pressure and the viscous shear stresses and also lends itself to complex geometries featuring non-matching grids at the fluid-solid interface. The level of tightness of the coupling on the aeroelastic response is investigated and the efficiency and accuracy of different solution strategies are discussed. The technology has been validated on well documented aeroelastic configurations