2018/4/27 Stability and Control Related 图上唐大学 Aircraft Control Surfaces Components 国上清大学 The following aircraft component/systems are important in aircraft stability and control -Weight and balance -Tall design -Control surfaces -Aerodynamic design Design criteria -Stability and control system meet the mission SPEED requirements G5钟0aa5 -Specifications on handling qualities are given in various standards GJB185-86(military aircraft) FAA/EASA/CAA Certification(civil aircraft) CONTROL SURFACES -LEAPNG EDGE FLAPS Intemet picture Stability Analysis 国上活大峰 Longitudinal and Lateral Stability 国上活大坐 Most aircraft are symmetrical,therefore: ·Pitch moment Stability analysis decoupled into ·Yaw moment -Longitudinal analysis (pitch only) A Lateral-directional analysis(roll and yaw) Static and Dynamic stability -Static stability provides the first step for achieving reasonable flying qualities Features of static instability can provide enhanced manoeuvrability -Dynamic stability is important to handling quality m■m0w-C,(X-X) oernan Wen ong 参考资料：顾通芬，飞机息体授计。 Moment coefficients 国上清大学 Linear Approximation of Moment Coefficients 图上活大坐 Moment coefficients are defined as Using first-order Taylor series expansion Cm =M/aSc Cn N/qSb C L/qSb Cm=Cmo+Cma园+Cms.园+Cmh where,and b are the MAC (mean aerodynamic chord)and wing span AAelevator deflection incidence of horitontal stabilizer Stability analysis is mainly concerned with aircraft response to changes in angular orientation CL=C1o+CigB+Cm5g8a+Cms,8r as sta Cn Cno+CneB+Cnoad+Cno.6 Cma Cig Cng side slip angle aileron deflection rudder deflection These explains the concept of stability coefficients 32018/4/27 3 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Stability and Control Related Components • The following aircraft component/systems are important in aircraft stability and control – Weight and balance – Tail design – Control surfaces – Aerodynamic design • Design criteria – Stability and control system meet the mission requirements – Specifications on handling qualities are given in various standards • GJB185-86 (military aircraft) • FAA/EASA/CAA Certification (civil aircraft) 13 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Aircraft Control Surfaces 14 Internet picture © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Stability Analysis • Most aircraft are symmetrical, therefore: • Stability analysis decoupled into – Longitudinal analysis (pitch only) – Lateral-directional analysis (roll and yaw) • Static and Dynamic stability – Static stability provides the first step for achieving reasonable flying qualities – Features of static instability can provide enhanced manoeuvrability – Dynamic stability is important to handling quality 15 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Longitudinal and Lateral Stability • Pitch moment • Yaw moment 16 参考资料：顾诵芬，飞机总体设计 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Moment coefficients • Moment coefficients are defined as 𝐶௠ = 𝑀/𝑞𝑆𝑐̅ 𝐶௡ = 𝑁/𝑞𝑆𝑏 𝐶௟ = 𝐿/𝑞𝑆𝑏 • where, 𝑐̅and 𝑏 are the MAC (mean aerodynamic chord) and wing span • Stability analysis is mainly concerned with aircraft response to changes in angular orientation – Derivatives of these coefficients w.r.t. AOA and sideslip angle are therefore referred to as stability derivatives 𝐶௠ഀ , 𝐶௟ഁ , 𝐶௡ഁ 17 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Linear Approximation of Moment Coefficients • Using first-order Taylor series expansion • These explains the concept of stability coefficients 18 AOA elevator deflection incidence of horizontal stabilizer side slip angle aileron deflection rudder deflection