Adaptive CFD analysis for rotorcraft aerodynamics

摘要

An adaptive, parallel computational fluid dynamics (CFD) technique is developed to compute rotor-blade aerodynamics. For this purpose an error indicator is formulated and coded into an adaptive finite element framework. It is shown that the error indicator is effective in resolving the global features of the flow-field. Furthermore, for efficiency and problem size considerations, once the interpolation errors are reduced to acceptable levels, the adaptive refinement is done only in regions affected by the vortical flows. To accomplish this, a novel vortex core detection technique is used to capture vortex tubes. The combination of interpolation error estimate and vortex core detection technique proved to be very effective in computing vortical flow-field of rotor blades. Example adaptive, parallel calculations of hovering rotor blades, requiring l-3 million tetrahedral elements, are presented.