The velocity profile in the boundary layer can be approximately described by the statement which likewise satisfies the boundary conditions w x (y = 0) = 0; w x (y = δ) = w δ ; (∂w x /∂y) y =0 = 0 and...

The velocity profile in the boundary layer can be approximately described by the statement

which likewise satisfies the boundary conditions

w_x(y = 0) = 0; w_x(y = δ) = w_δ; (∂w_x/∂y)_y=0 = 0 and (∂²w_x/∂y²)_y=0 = 0 .

Calculate the thickness of the boundary layer δ(x).

Hot air at 300 ◦C and a pressure of 0.01 MPa flows at a velocity of 10 m/s over a 1 m long, flat plate. What heat flow must be removed per m2 of the plate surface area if we want to maintain the plate temperature at 25 ◦C?

Given are kinematic viscosity ν₁(p₁
= 0.1 MPa, ϑ_m
= 162.5 ◦C) = 30.84 · 10⁻⁶
m²/s, the Prandtl number P r(ϑ_m
= 162.5 ◦C) = 0.687 and the thermal conductivity of air λ(ϑ = 162.5 ◦C) = 3.64 · 10⁻²
W/Km.