The flow inside the boundary-layer over a flat plate can be considered: (a) invi
ID: 1939122 • Letter: T
Question
The flow inside the boundary-layer over a flat plate can be considered:(a) inviscid flow .
(b) viscous flow.
(c) fully developed turbulent flow.
(d) fully developed laminar flow.
All of the following parameters are sources of minor losses in a viscous flow in a pipe EXCEPT:
(a) inlets and exits.
(b) pipe bends.
(c) valves and fittings.
(d) pipe length.
For a fully developed viscous laminar flow in a pipe, the maximum shear stress locates at:
(a) pipe centreline.
(b) pipe entrance
(c) pipe walls.
(d) pipe exit.
Explanation / Answer
1 Answer is (b), since a boundary layer is the layer of fluid in the immediate vicinity of a bounding surface where the effects of viscosity are significant. WIthout viscosity, there is no boundary layer. 2 Answer is (d). The length of the pipe determine the friction (major loss or head loss) loss. 3 Answer is (c), since the velocity gradient is maximum at the wall. Note, at the ceter for a circular pipe, the shear stress is zero.