Computational Fluid Dynamics–Computational Structural Dynamics Rotor Coupling Using an Unstructured Reynolds-Averaged Navier–Stokes Methodology

Abstract

The focus of this paper is to discuss the unique challenges introduced through the use of unstructured grids in rotorcraft computational fluid dynamics (CFD)-computational structural dynamics (CSD) coupling. The use of unstructured grid methodology in CFD has been expanding because of the advantages in grid generation and modeling of complex configurations. However, the resulting amorphous distribution of the grid points on the rotor blade surface provides no information with regard to the orientation of the blade, in direct contrast to structured grid methodology that can take advantage of the ordered mapping of points to identify the orientation as well as simplifying airloads integration. A methodology has been developed and is described here, which now permits unstructured methods to be utilized for elastic rotary-wing simulations. This methodology is evaluated through comparison of the UH60A rotor with available flight test data for forward flight.

Computational aeroelastic analysis of slowed rotors at high advance ratios

“…The case of a rigid four-bladed model was examined by Ormiston (22) comparing both linear aerodynamics and a simple stall model. In contrast, CFD-CSD coupled methods (23)(24)(25)(26)(27)(28)(29)(30)(31) include URANS CFD modules to provide an increased fidelity of aeroelastic analysis via the more accurate simulation of the physics associated with viscous and vorticity influences on the rotor, albeit at higher computational cost and time requirements.…”

High-Fidelity Multidisciplinary Design Optimization Methodology with Application to Rotor Blades

“…A FUN3D/DYMORE5 interface has been developed to exchange aerodynamic loads and structural deflections between high-fidelity aero and structural dynamics models (Ref. 25). This interface has been extended to enable multidisciplinary sensitivity analysis that integrates adjoint-based CFD sensitivities and complex-variable CA sensitivities.…”

Overset meshing coupled with hybridizable discontinuous Galerkin finite elements

“…The two other issues are how to address orphan points and hole cutting. Orphan points are created when there is no suitable donor cell [6][7][8][9]. Cutting holes in a mesh can eliminate orphans but can also lead to voids in the discretized domain [10][11][12][13].…”

“…The convection-diffusion problem over a single mesh in the overset system is stated as follows. The only substantive change from (7) to (19) is in (19c): We have added in terms over the overset portion of the boundary. The values ofȗ h ,q h , andn come from some T h,j ≠ T h,i that is yet to be specified.…”