2.6 Forces Imposed by Fluid Flow
a
square cylinder
half-cylinder
flow
thin plate normal to wall
half-cylinder
b
G lj
LlD C
107
L
1 0.64
.
3 0.72
10 0.82
flow cube
'----+
short cylinder
8EOdD
c
flow
sphere
solid hemi hpere
-.. CdA = 0.836 m
1
t CdA = 0. 111 m
1
average person
ellipsoid
snail
0.0043
barnacles
small mackerel
57
0]
cylinder
elliptical cylinder (2: 1)
LID C
2 0.27
4 0 . 25
cone
9 C
J(f' 0.30
2(f' 0.40
3(f' 0.55
0.82
A
model T Ford
kelp
coral
Fig. 2.25: Drag coefficient for various shapes: a two-dimensional, b threedimensional, c living organisms; A denotes surface of human body (adapted from
Denny, 1988; Vogel, 1994; White, 1994)