Rotorcraft Model Enhancements to Support Land and Sea-Based Testing and Operational Analysis

Period of Performance: 06/25/1998 - 06/25/2000


Phase 2 SBIR

Recipient Firm

Advanced Rotorcraft Technology, Inc.
635 Vaqueros Avenue Array
Sunnyvale, CA 94085
Principal Investigator

Research Topics


The proposed enhancement of rotocraft simulation to support land and sea-based flight testing and operational analysis is intended to resolve the long-time perplexing problems related to the fundamental simulation requirement for an accurate prediction of the helicopter response throughout the flight envelope. The solution proposed is to enhance the widely used finite state dynamic wake model with the effect of rotor wake distortion and to provide rotor and fuselage aerodynamic interference and fuselage airload prediction capability in a comprehensive flight simulation program. The resulting comprehensive modeling capability will provide a unified simulation environment in support of rotocraft design and operation. The new formulation will approach the problem in a systematic way and address the interaction of various disciplines related to the simulation modeling. The main innovations of this proposal can be summarized as follows: (1) Inclusion of the tip vortex distortion effect in the finite state dynamic wake model to overcome the poor prediction of rotocraft off-axis response. (2) Modification of the finite state dynamic wake model to include the vortex ring state, extending the simulation to be applicable across the flight envelope. (3) Enhancement of finite state dynamic wake model for an unsteady aerodynamic interference of the rotor on the fuselage, other rotors and aerodynamic lifting surfaces. (4) Development of a fuselage panel airload calculation model to enhance existing rotocraft flight simulations that still rely heavily on fuselage empirical data. (5) Integration of the enhanced finite state dynamic wake model and panel airload model into a comprehensive simulation program (FLIGHTLAB) so that the inter-disciplinary couplings will be addressed.