An average value of ∂u/∂y for a boundary-layer thickness is ue/δ (u rises from zero at y = 0 to ue at y = δ);an average value of ∂2u/∂y2 can be derived by a similar argument: δu/δy changes from a value of order ue /δ at y = 0 to zero at y = δ, so an average value of ∂(∂u/∂y)/∂y ≡ ∂2u/∂y2 is of order ue/δ2. The velocity at a fixed distance y from the surface, where y is smaller than the value of 6 at the streamwise position considered, falls from ue at the boundary-layer origin, x = 0, to a value rather smaller than ue at the stream-wise position considered.
KeywordsStreamwise Position Heat Transfer Term Viscous Diffusion Term
Unable to display preview. Download preview PDF.