The high rate of accidents in general aviation due to pilot loss of control has necessitated the need to find better methods of training pilots. Pilot control and awareness in the stall/post-stall regime can be improved through the use of higher fidelity flight simulators. To create a high fidelity aerodynamic model in the stall/post-stall regime to be implemented in a flight simulator, both steady and unsteady aircraft characteristics need to be represented. In this paper, the detailed development of a steady-state general aviation aircraft stall/post-stall longitudinal aerodynamic model is described. The steady-state model uses a component buildup approach that uses strip theory to output the aerodynamic forces and moments of an aircraft. An integrated non-linear lifting-line theory approach is used to model the wing and horizontal tail. Longitudinal effects due to elevator deflections are also included. Validation studies are performed against static wind tunnel datasets for a typical single-engine low-wing general aviation aircraft design.
Nomenclatureairfoil moment coefficient at quarter chord C M c/4 = surface moment coefficient at quarter chord (= M/ 1 2 ρV 2 ∞ S ref c) C N = surface normal force coefficient (= N/ 1 2 ρV 2 ∞ S ref ) C n = local normal-force coefficient per unit length * Graduate Student (Ph.D. Candidate), 104 S. Wright St., AIAA Student Member. anandak1@illinois.edu † Professor, 104 S. Wright St., AIAA Associate Fellow. m-selig@illinois.edu 1 of 25 American Institute of Aeronautics and Astronautics Downloaded by PURDUE UNIVERSITY on June 22, 2016 | http://arc.aiaa.org | AIAA Aviation d F = fuselage cross-section diameter D = drag D ind = induced drag k = corner radius l ref = reference length l F = fuselage length L = lift M = moment n P = number of lifting surface panels N = normal force r F = fuselage cross-section radius Re = Reynolds number based on mean aerodynamic chord (= V ∞ c/ν) S = lifting surface area S f = flap area S ref = reference area V ∞ = freestream velocity V F = fuselage volume w ind = velocity induced by shed vortices V rel = relative velocity w F = fuselage width x F = axial distance from fuselage nose x ac F = distance from nose to aerodynamic center of fuselage x c F = distance from nose to centroid of fuselage planform area x m F = distance from nose to centroid of fuselage pitching-moment reference center x P S , y P S , z P S = location of spanwise panel station points x LLT , y LLT , z LLT = location of lifting-line points Y = side force α ef f = effective angle of attack α geo = geometric angle of attack α ind = induced angle of attack β = sideslip angle δ f = flap deflection angle η = flap effectiveness correction factor η f use = fuselage crossflow drag proportionality factor Γ = circulation Γ 0 = circulation at center-span Γ LLT = circulation at the lifting-line points Γ SV = shed vortex circulation τ = flap effectiveness factor θ f = factor relating flap to chord ratio to flap effectiveness factor ν = kinematic viscosity ρ = density of air Subscripts c/4 = ...