Enhanced Flight Dynamics Models with Aerodynamic Interference for Real-Time Simulation of VTOL Concept Vehicles

In an effort to establish common models to support the Advanced Air Mobility (AAM) community, NASA has
designed a fleet of VTOL configuration reference models. Advanced Rotorcraft Technologies (ART) in cooperation
with the NASA Ames Aeromechanics branch has developed FLIGHTLAB simulation models for several of these AAM
VTOL concept vehicles. These simulation models are real-time capable while maintaining accurate flight dynamic
characteristics with enhanced interference simulation by extracting important modeling parameters from Viscous Vortex
Particle Method (VVPM). The focus of this paper is threefold. First, it introduces the simulation models developed and
describes their modeling characteristics important to control and flight dynamics simulation. Second, the method for
deriving the interference coefficients between model components such as rotors and wings is outlined. Implementation
of the method for the lift+cruise and tiltwing models are discussed in detail. Third, the accuracy of the interference
enhancement is assessed, with emphasis placed on the impacts to trim and flight dynamic characteristics. The
interference enhancement method is further used to evaluate configuration design decisions by quantifying performance
aspects of interference. This research effort culminated in simulation models for the AAM VTOL concept vehicles, with
proper interference and real-time capability.