The maximum thickness of boundary layer in a pipe of radius r is
The thickness of the boundary layer represented, by 8(greek 'delta’) is arbitrarily defined as that distance from the boundary surface in which the velocity reaches 99% of the velocity of the main stream, in a pipe the free stream velocity is at the centre of the pipe. Therefore maximum thickness of boundary layer is r.
The velocity profile for turbulent boundary layer is:
Velocity profile follows 1/7th power law for turbulent boundary layer.
The drag force experienced by an object in a fluid stream is
The correct relationship among displacement thickness ‘d’ momentum thickness ‘m’ and energy thickness ‘e’ is
What is the momentum thickness for the boundary layer with velocity distribution u/U = y/δ ?
The momentum thickness is given by,
If x is the distance from leading edge, then the boundary layer thickness in laminar flow varies as
If δ1 and δ2 denote the boundary layer thicknesses at a point distance x from the leading edge on a fiat plate when the Reynolds numbers are 100 and 256 respectively, then the ratio of δ1 to δ2 will be
If δ1 is the thickness of laminar boundary layer at a distance x1 from the leading edge of the flat plate, the thickness δ2 at x2 = 2x1 is equal to
For laminar boundary layer,
The displacement thickness δ* of a boundary layer is defined as δ* =
Separation of boundary layer takes place under