Up-wind t
heoretical
profile
Speed up
A
a
b
c
B
C
D
0
0
U A
U D
z f
L 1/2
z 1
Hill height
E
F
∆z
∆z
Flat top ridge
Hight turbulence
2
3
1
Wind profiles
are the same
Region of
increased flow
Fig. 5.12 Schematic of air circulation over isolated hills with different profiles. a gently sloping
hill, b flat-topped hill, and c theoretical conical hill after Stull (1994); b and c after Rohatgi and
Nelson (1994)
5.5 Flow Over Gently Sloping Hills
151
heoretical
profile
Speed up
A
a
b
c
B
C
D
0
0
U A
U D
z f
L 1/2
z 1
Hill height
E
F
∆z
∆z
Flat top ridge
Hight turbulence
2
3
1
Wind profiles
are the same
Region of
increased flow
Fig. 5.12 Schematic of air circulation over isolated hills with different profiles. a gently sloping
hill, b flat-topped hill, and c theoretical conical hill after Stull (1994); b and c after Rohatgi and
Nelson (1994)
5.5 Flow Over Gently Sloping Hills
151