Question: A thin plate of length 50 cm is held in uniform water flow such that its length is parallel to the flow direction. The flow speed is 10 m/s; the viscosity, µ = 1.0 × 10-3 Pa/s; and the water density, 998 kg/m3.
(a) What is the Reynolds number based on plate length? What can be deduced from its value?
(b) On the assumption that the boundary layer is laminar over the whole surface, use the approximate theory based on the momentum-integral equation to find
• The boundary-layer thickness at the trailing edge of the plate
• The skin-friction drag coefficient
(c) Repeat (b), but now assume that the boundary layer is turbulent over the whole surface. (Use the formulae derived from the one-seventh-power-law velocity profile.)