Problem

A zeppelin airship (Figure 6.51) travels at an elevation of 300 m at a speed of 60 km/hr....

A zeppelin airship (Figure 6.51) travels at an elevation of 300 m at a speed of 60 km/hr. The length of the zeppelin is 75 m and the diameter is 18 m. Using the drag coefficient of a streamlined body from Table 6.2, calculate the drag force and the power required to overcome drag.

Figure 6.51 Picture of a zeppelin. Courtesy of ZeppelinNT.

Table 6.2

Type	CD	Shape
Sphere	0.45
Cylinder	1.2
Hemisphere—facing toward flow	0.4
Hemisphere—facing away from flow	1.4
Cube	1.05
Flat plate perpendicular, square and rectangle
Square	1.05
2 by 1 rectangle	1.1
Long rectangle	2.0
Circular disk flat plate	1.1
Cone—120° angle	0.92
Streamlined body	0.025
Cylinders of various cross sections
Square	2.1
Diamond	1.6
Ellipse (2:1 ratio)	0.6
Ellipse (8:1 ratio)	0.2
Triangle (equilateral)	1.3
Triangle (30° apex)	1.0
Open arc (C-section) facing away from flow	1.1
Open arc (C-section) facing toward flow	2.3
Data from [NACA34], [NACA36], [NACA38], [NACA53], [Goldstein65], [Hoerner65], [Schlicting68], and [NASA71].