Accession Number : ADA256438


Title :   Wing Rock Prediction Method for a High Performance Fighter Aircraft


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING


Personal Author(s) : Nolan, Robert C , II


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a256438.pdf


Report Date : May 1992


Pagination or Media Count : 125


Abstract : This study is a limited investigation of the nonlinear aircraft behavior known as wing rock. An eight state F-15 model is analyzed using bifurcation theory. The wing rock onset point is identified and small perturbation analysis is used to linearize the equations of motion about this point. The eigenstructure of the model is analyzed and is used to identify the stability modes involved in this motion. A procedure is developed to predict wing rock onset and frequency and the critical stability derivatives involved in this motion are identified. The developed procedure is applied to existing F-4J data and a flight test involving RF-4C and T-38A aircraft is flown The results show wing rock is an unstable dutch roll motion and the developed wing rock prediction parameter is accurate to within 1 degree of onset AOA. The frequency prediction parameter gives a fair estimate of wing rock motion but it may be adversely influenced by the type of flight test data. The slope of the prediction parameter versus AOA curve may be an indication of the severity of wing rock motion. Stability and control, bifurcation (mathematics), wing rock, roll oscillations, flight test, high AOA.


Descriptors :   *FIGHTER AIRCRAFT , *ROLL , *AERODYNAMIC STABILITY , *TRAINING AIRCRAFT , *WINGS , TEST AND EVALUATION , FREQUENCY , AIRCRAFT , MODELS , THEORY , ANGLE OF ATTACK , BIFURCATION(MATHEMATICS) , OSCILLATION , BEHAVIOR , PERTURBATIONS , SLOPE , FLIGHT , ROCK , MOTION , PARAMETERS , PERFORMANCE(ENGINEERING) , PREDICTIONS , EQUATIONS OF MOTION , STABILITY , CONTROL


Subject Categories : Aerodynamics
      Attack and Fighter Aircraft
      Training Aircraft


Distribution Statement : APPROVED FOR PUBLIC RELEASE