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Change in boundary layer from laminar to turbulent is directly affected by (i) Roughness of plate (ii) Pressure gradient (iii) Intensity of turbulence (iv) Velocity of flow Which of the above-mentioned option(s) is/are incorrect?

Change in boundary layer from laminar to turbulent is directly affected by (i) Roughness of plate (ii) Pressure gradient (iii) Intensity of turbulence (iv) Velocity of flow Which of the above-mentioned option(s) is/are incorrect? Correct Answer Only (iv)

Explanation:

Change in the boundary layer from laminar to turbulent is affected by:

a) Roughness of the plate

b) Plate Curvature

c) Pressure gradient

d) Intensity and scale of turbulence

So, Change in boundary layer from laminar to turbulent is directly affected by all the three options (i), (ii) and (iii) and not affected by velocity of flow. Therefore, Option (iv) is incorrect.

Extra Points:

Boundary layer theory:

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  • When a fluid of ambient velocity flows over a flat stationary plate, the bottom layer of fluid directly contacts with the solid surface and its velocity reaches to zero.
  • Due to the cohesive forces between two layers, the bottom layer offers resistance to the adjacent layer and due to this reason, the velocity gradient develops in a fluid.
  • A thin region over a surface velocity gradient is significant, known as the boundary layer.

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