Question

(25 pts) A jet aircraft has the following features: C1,0 = 0.022, e=0.85, AR = 8.3, m = 6,032 kg, S = 30 m², Cl = 0.103a, TA = 22,240 N at sea level Calculate the followings: a) Minimum thrust required and the velocity at which it occurs at sea level b) Angle of attack corresponding to the minimum thrust required at sea level c) Maximum velocity at sea level d) Minimum required thrust for this aircraft to fly at 10,000 m altitude

Answer 1

Questions given of Coo = 0.022, & - 0185 A.R. = 8.3 m = 6032 kg S= 30 m² = 0.1034 TA = 22240 N Cat sea level). Becouse @ Minimum thouet required and the Velocity at which it oceurs at Sea Levele at Sea Level means there is no lift So we take Drag Coefficient at Zero lift C Cool. Haircraft = mg = 6032 x 9.81 1 - 5 1 3 att 0 plet force = K - TA I Het = 59173.gq - 22950 VN fret = 36933.94 Drag or thout force at Sea Level & to & Co.ox fhet. fo = 0.022 x 369 33.9

fo=812.54 N Nho. Minimum Velocity el m2 fo & Co,o x 1 x P AVE S'A=S=300 812.54 = 01022x tx l. 2x 30 x02 | v = 45,297 m/pec. LA D Angle of attack Corresponding to mi fchouet' at 'Sea Level . + Lift induced drag (Co,i). inimum a Chi = al . (0.103212 bi - AXAR.ye - XX 8.3 xor85 Coil = 4 1786 810 * 227 Fomin. = Coi x t x P A 12 812.54 = 4 1786 x 10 * 2² x tx 112 x zox. a (451297) 22 = 45.968

- Ane © Maximum Velocity at Sea Level 7 maximum Itol Drag occur at Sea - they. Leved in equal to ite weight and multiplication of Coo (fo) now. = (6032) x 91818 01022 fomane. = 1301.82 N T har. fo = Coox tx ga va 1301182 = 00022 xL xli2x30xV2 v2 = 328 7. et Vanny = 57.336 mleen And Minimum required threrst for this aircraft fby 10000 m altitude W = 6039x9.81 I W = 59 17 3.92 N T

At 10ooom altitude only lweight ie taken - for accounting the thanket Total drag & Co z logo + Coil Co = 0.022 + 4.786x10 " x (626) 2 . Co z 010419.1 fo - Cox W In = 0.0419 x 59 173.92 For a 2483.69 N 'mininum