Manipulation of turbulent flow for drag reduction and heat transfer enhancement 6

ω x

40 10 4 1.5 0 -1.5 -4 -10 -40

flow direction

Plane 2

Plane 1

Plane 7

Plane 4

Plane 6

Plane 5

Plane 3

I

1

y 0 -1

z y

(a) h/D = 10%

Z

ω x

40 10 4 1.5 0 -1.5 -4 -10 -40

flow direction

Plane 2

Plane 1

Plane 7

Plane 4

Plane 6

Plane 5

Plane 3

I

1

y 0 -1

z y

(b) h/D = 20%

Figure 5.13: Streamwise vorticity (ω x) and streamlines on different Z-Y

plane slices, red dashed lines refer to boundary of protrusions

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