The maximum thickness of boundary layer in a pipe of radius r is

Related MCQs

• The boundary layer thickness at a distance of l m from the leading edge of a flat plate, kept at zero angle of incidence to the flow direction, is O.l cm. The velocity outside the boundary layer is 25 ml sec. The boundary layer thickness at a distance of 4 m is (Assume that boundary layer is entirely laminar.)
• The distance y from pipe boundary, at which the point velocity is equal to average velocity for turbulent flow, is (where R is radius of pipe.)
• The distance from pipe boundary, at which the turbulent shear stress is one-third die wall shear stress, is (where R is the radius of pipe.)
• According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe)
• The diameter of the nozzle (d) for maximum transmission of power is given by (where D = Diameter of pipe, f = Darcy’s coefficient of friction for pipe, and l = Length of pipe)
• The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v = Velocity of the liquid in the pipe, μ = Viscosity of the liquid, and w = Specific weight of the flowing liquid)
• The correct relationship among displacement thickness d, momentum thickness m and energy thickness e is
• If x is the distance from leading edge, then the boundary layer thickness in laminar flow varies as
• The boundary layer thickness in turbulent flow varies as (where x is the distance from leading edge.)
• When time of closure tc = L/v0 (where L is length of pipe and v0 is speed of pressure wave), the portion of pipe length subjected to maximum head is