General Aviation Configuration Simulation Development Support
Following
an examination of measured wind tunnel data for a proposed General Aviation
aircraft design, it was determined that the particular configuration
would be expected to have unacceptable pitch characteristics in the
stall region.
The goal of an effort undertaken by Bihrle was to systematically identify methods to alleviate these unfavorable aerodynamic characteristics through exploratory wind tunnel testing and simulation analysis. These exploratory tests were being made to address issues in the early stages
of the development of the configuration. A series of wind tunnel tests were conducted to evaluate the aerodynamic characteristics of the baseline aircraft and for a number of promising configuration modifications.
As part of this study to aid in the development of the configuration, these data were assembled into a nonlinear large-angle high-fidelity aerodynamic math model representation of the General Aviation configuration and implemented in the Bihrle D-Six simulation environment to predict
the aircraft's flight motions, including departure and deep-stall conditions. Once this capability was established, incremental effects of various promising configuration modifications were then evaluated for their influence on the aircraft's departure characteristics and resistance to
deep-stall.
An evaluation of stall characteristics in the simulation study performed by Bihrle revealed that the basic aircraft configuration exhibited a pronounced tendency to enter a deep-stall during routine stalls. The aircraft exhibited a pitch excursion through 50 degrees angle of attack
and, in the case with the flaps deflected the deep-stall condition was captured even after the application of forward stick. Several of the configuration modifications examined exhibited satisfactory stall behavior for both zero and full flap conditions at the aft cg limit and precluded
any deep-stall entry.
Recommendations from this analysis led to the final configuration design followed by FAA certification of the actual aircraft.
Stall characteristics of the baseline configuration with flaps deflected
Stall characteristics of the modified configuration with flaps deflected
Other Simulation Development and Support Success Stories
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F/A-18C/D
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The
Wright Flyer Model B Simulator
Grumman
EA-6B Engineering Simulation
Ice Contamination Effects Flight Training Device (ICEFTD) for NASA Glenn Research Center
F-16
WST Flight Model Update
