Implementation of DYMORE (CSD)/Overflow-2 (CFD) Loose Coupling Methodology at BHTI

Even though comprehensive analysis (CA) codes have brought great success to the rotorcraft community, there are some aerodynamic phenomena that are not well captured by these codes yet. Because of this, the rotorcraft community has increasingly focused in the coupling of computational structural dynamics (CSD) with computational fluid dynamics codes (CFD). This paper presents an implementation of a loose coupling methodology between DYMORE and OVERFLOW-2. Numerical results for two different rotor configurations under relatively benign flight conditions will be presented. For both of these two cases, good convergence of trim target values were achieved. For the Bell 427 case, structural load wave forms from CFD/CSD are in better agreement with flight test data, when compared to CA predictions. This indicates that CFD/CSD is better capturing the physics of the problem and therefore should provide an improvement in prediction over lifting line aerodynamics for more severe flight conditions.