16.885J/ESD. 35J-Sept 2003 16.885J/ESD.35J Aircraft systems engineering Aerodynamics Primer Prof earll murman
16.885J/ESD.35J - Sept 2003 16.885J/ESD.35J Aircraft Systems Engineering Aerodynamics Primer Prof. Earll Murman
16. 885J/ESD. 35J-Sept 2003 TopIcs Geometry jargon Standard atmosphere Airflow variables Forces acting on aircraft Aerodynamic coefficients Lift curve Drag polar Reference: Anderson. John D Jr. Introduction to Flight McGraw Hill, 3rd ed. 1989. All figures in this primer are taken from this source unless otherwise noted Note other sources need to be added
16.885J/ESD.35J - Sept 2003 Topics • Geometry jargon • Standard atmosphere • Airflow variables • Forces acting on aircraft • Aerodynamic coefficients • Lift curve • Drag polar • Reference: Anderson, John D. Jr. Introduction to Flight, McGraw Hill, 3rd ed. 1989. All figures in this primer are taken from this source unless otherwise noted. • Note: other sources need to be added
16.885J/ESD. 35J-Sept 2003 Wing and Airfoil Nomenclature t= thickness c= chord t/c is an airfoil parameter
16.885J/ESD.35J - Sept 2003 Wing and Airfoil Nomenclature t = thickness c = chord t/c is an airfoil parameter t c V 8
16.885J/ESD. 35J -Sept 2003 More wing nomenclature C b=wing span ·S= wing area AR=aspect ratio=b2/S For c.=S/b ar= b/c vg avg 入=c/c.= taper ratio b A=leading edge sweep angl le Twist is the difference in the angle of the tip and root airfoil section chord lines
16.885J/ESD.35J - Sept 2003 More Wing Nomenclature b S cr ct / • b = wing span • S = wing area • AR = aspect ratio=b2/S – For cavg = S/b, AR= b/cavg • O = ct/cr = taper ratio • / = leading edge sweep angle • Twist is the difference in the angle of the tip and root airfoil section chord lines
Standard Atmosphere The environme Bo3 16.885J/ESD. 35J-Sept for aircrat aft design The" standard atmosphere is a reference condition every day is different Temperature T, pressure p, density p are functions of altitude h Standard sea level conditions p=101325x105N/m2=2162bf2 T=288160K=518.7R p=1.2250kgm3=000278sug/ft Handy calculator http://aero.stanford.edu/stdatm.html
16.885J/ESD.35J - Sept 2003 Standard Atmosphere: The Environment for Aircraft Design • The “standard atmosphere” is a reference condition. – Every day is different. • Temperature T, pressure p, density U are functions of altitude h. • Standard sea level conditions – p = 1.01325x105 N/m2 = 2116.2 lb/ft2 – T = 288.16 0K = 518.7 0R – U = 1.2250 kg/m3 = 0.00278 slug/ft3 • Handy calculator http://aero.stanford.edu/StdAtm.html