title: Skin friction in zero-pressure-gradient boundary layers.
abstract: A global approach leading to a self-consistent solution to the Navier-Stokes-Prandtl equations for zero-pressure-gradient boundary layers is presented. It is shown that as Re(δ)→ ∞, the dynamically defined boundary layer thickness δ(x) ∝ x/ln2  Rex and the skin friction λ = 2τ(w)/ρU(0)(2) ∝ 1/ln2  δ(x). Here τ(w) and U0 are the wall shear stress and free stream velocity, respectively. The theory is formulated as an expansion in powers of a small dimensionless parameter dδ(x)/dx → 0 in the limit x → ∞.
authors.affiliation: Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, USA. vy@bu.edu
authors.forename: Victor
authors.initials: V
authors.lastname: Yakhot