Extension of a discontinuous Galerkin finite element method to viscous rotor flow simulations

Heavy vibratory loading of rotorcraft is relevant for many operational aspects of helicopters, such as the structural life span of (rotating) components, op- erational availability, the pilot’s comfort, and the ef- fectiveness of weapon targeting systems. A precise understanding of the source of these vibrational loads has important consequences in these application ar- eas. Moreover, in order to exploit the full poten- tial offered by new vibration reduction technologies, current analysis tools need to be improved with re- spect to the level of physical modeling of flow phe- nomena which contribute to the vibratory loads. In this paper, a computational fluid dynamics tool for rotorcraft simulations based on first-principles flow physics is extended to enable the simulation of vis- cous flows. Viscous effects play a significant role in the aerodynamics of helicopter rotors in high-speed flight. The new model is applied to three-dimensional vortex flow and laminar dynamic stall. The applica- tions clearly demonstrate the capability of the new model to perform on deforming and adaptive meshes. This capability is essential for rotor simulations to accomodate the blade motions and to enhance vor- tex resolution.

[1]  Bernardo Cockburn,et al.  Discontinuous Galerkin Methods for Convection-Dominated Problems , 1999 .

[2]  Jaap J. W. van der Vegt,et al.  Space-Time Discontinuous Galerkin Method for the Compressible Navier-Stokes , 2006 .

[3]  S. P. Spekreijse,et al.  Efficient and accurate implementation of the k-omega turbulence model in the NLR multi-block Navier-Stokes system , 2000 .

[4]  Berend G. van der Wall,et al.  Progress in Weak Fluid-Structure-Coupling for Multibladed Rotors in High-Speed forward Flight , 2002 .

[5]  M. Costes,et al.  A weak coupling method between the dynamics code HOST and the 3D unsteady Euler code WAVES , 2001 .

[6]  O. J. Boelens,et al.  A framework for aeroelastic simulations of trimmed rotor systems in forward flight , 2004 .

[7]  Berend G. van der Wall,et al.  Chimera simulations of multibladed rotors in high-speed forward flight with weak fluid-structure-coupling , 2005 .

[8]  M. Visbal,et al.  Investigation of the flow structure around a rapidly pitching airfoil , 1989 .

[9]  O. J. Boelens,et al.  Boundary Conforming Discontinuous Galerkin Finite Element Approach for Rotorcraft Simulations , 2002 .

[10]  Hubert Pomin,et al.  Aeroelastic Analysis of Helicopter Rotor Blades on Deformable Chimera Grids , 2004 .

[11]  R. Rudnik,et al.  Overview About the European High Lift Research Programme EUROLIFT , 2004 .

[12]  Timothy J. Barth,et al.  High-order methods for computational physics , 1999 .

[13]  Martin Lowson,et al.  Development of a three-dimensional free shear layer , 1998, Journal of Fluid Mechanics.

[14]  Urmila Ghia,et al.  Simulation of dynamic stall phenomenon using unsteady Navier-Stokes equations , 1991 .

[15]  Hubert Pomin,et al.  Aeroelastic Analysis of Helicopter Rotor Blades on Deformable Chimera Grids , 2002 .

[16]  H. van der Ven,et al.  Space-time discontinuous Galerkin finite element method with dynamic grid motion for inviscid compressible flows. Part II. Efficient flux quadrature , 2002 .

[17]  J Vandervegt,et al.  Space–Time Discontinuous Galerkin Finite Element Method with Dynamic Grid Motion for Inviscid Compressible FlowsI. General Formulation , 2002 .