A flying wing has a planform area of 3700 ft2, a rootchord at the airplane centerline of 34 ft, an overall taper ratioof 0.275, and a span of 170 ft. The average weighted airfoilthickness ratio is 10.2% and the wing has 36 degrees of sweepbackat the 25% chordline. The air- plane is cruising at a pressurealtitude of 17,000 ft on a standard day with a wing loading of 40lb/ft2. The cruise Mach number is 0.30. Determine thefollowing:
(a) skin-friction drag coefficient (assume a spray-paintedsurface)
(b) pressure drag coefficient
(c) induced drag coefficient
(d) total drag coefficient
(e) total drag in pounds
Remember that a wing has both upper and lower surfaces exposedto the flow. Use the appropriate skin friction coefficient equation(Chp 4) that would include transition from laminar to turbulent;assume Re,trans = 500,000. If the surface is fully-rough, thenconsult 5.20 on pg 266. Form drag is based on the fineness ratiocharts. The Oswald efficiency factor is high for wings—assume e =0.95.
