Question

For laminar flow over a flat plate, the thickness of the boundary layer at a distance from the leading edge is found to be 5 mm. The thickness of the boundary layer at a downstream section, which is at twice the distance of the previous section from the leading edge, will be
1. 10 mm
2. \(5\sqrt 2 mm\)
3. \(\frac{5}{{\sqrt 2 }}mm\)
4. 2.5 mm

Answer 1

Correct Answer - Option 2 : \(5\sqrt 2 mm\)

δ ∝ √x

\(\frac{{{\delta _2}}}{{{\delta _1}}} = \sqrt {\frac{{{x_2}}}{{{x_1}}}} = \sqrt 2 \)

∴ δ₂ = 5√2 mm