Weight (W) 15,000 lb CDP 0.021
Wing Area (S) 230 ft2 CLmax at Stall 1.5
Aspect Ratio (AR) 5.3 Note: Assume the drag polar is a parabola
Span Efficiency (e) 0.85
Temperature Standard
Altitude Sea Level
Complete the following table for this particular typical transport jet. Start the table at stall speed, VS. Then answer the questions at the end using the values from the table. You can use an excel spreadsheet to create the answers for the table.
|
V
(KTAS)
|
q
(psf)
|
CL
|
CD
|
CL / CD
|
DP
(lb)
|
DI
(lb)
|
DT
(lb)
|
|
VS
|
|
|
|
|
|
|
|
|
120
|
|
|
|
|
|
|
|
|
140
|
|
|
|
|
|
|
|
|
160
|
|
|
|
|
|
|
|
|
180
|
|
|
|
|
|
|
|
|
190
|
|
|
|
|
|
|
|
|
200
|
|
|
|
|
|
|
|
|
220
|
|
|
|
|
|
|
|
|
240
|
|
|
|
|
|
|
|
|
260
|
|
|
|
|
|
|
|
Equations for Table:
q = CL = CDi =[1/ (πeAR)] CL2
CD = CDP + CDi CD = CDP + [1/ (e AR)] CL2 Dp = CDp q S
Di = CDi q S = [1/ (e AR)] CL2 q S Dt = Di + Dp = CD q S
1. Determine VSTALL (Stall speed in KTAS).
2. Determine DMIN (Minimum total drag in pounds).
3. Determine VDMIN (Speed in KTAS at minimum drag).
4. Determine the parasitic drag at DMIN (pounds).
5. Determine the induced drag at DMIN (pounds).
6. Find Glide Ratio at VDMIN.