In the laminar flow of air (Pr = 0.7) over a heated plate if δ and δT denote, respectively, the hydrodynamic and thermal boundary layer thicknesses, then
δ < δT
Pr = ν/α = 0.7 means heat diffuses faster than momentum. Thus \(\delta_T/\delta\approx Pr^{-1/3}\gt 1\) and δ < δT.
Important Questions from Boundary Layer Theory
Friction drag is generally larger than the pressure drag in _______.
When a fluid flows along a solid boundary, more and more fluid gets retarded in the vicinity of the boundary. This deceleration is accompanied by:
A plate of 500 mm × 200 mm has been placed longitudinally in a stream of an oil which flows with a velocity of 1.0 m/s. The kinematic viscosity of the oil was 0.5 stoke. The thickness of the boundary layer at the trailing edge is _______.
As defined by Prandtl, in convective heat transfer, a thin layer next to the wall where shear stress is confined is called _____.
Thickness of laminar boundary layer on flat plate:
