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The thickness of the laminar boundary layer on a flat plate at a point A is 2 cm and at a point B, 1 m downstream of A, is 3 cm. What is the distance of A from the leading edge of the plate?
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- 0.50 m
- 0.80 m
- 1.00 m
- 1.25 m
Correct Option: B
As per Blasius equation,
→V = ui + vj
u = 2x + 3y , v = -2y
| = | , Re = | ||||
| x | √Re | μ |
∴ δ ∝ √x
x – distance from leading edge.
At x, δ1 = 2 cm
At x + 1, δ2 = 3 cm
| = | = | ||||
| δ2 | √x + 1 | 3 |
∴ x = 0.8 m.
