Small wind tunnels in an undergraduate laboratory have 305-mm square test sections. Measurements show the boundary layers on the tunnel walls are fully turbulent and well represented by 1 7-power...

Small wind tunnels in an undergraduate laboratory have

305-mm square test sections. Measurements show the

boundary layers on the tunnel walls are fully turbulent and

well represented by 1

7-power profiles. At cross section 1 with

freestream speed U1 5 26.1 m/s, data show that δ1 5 12.2

mm; at section 2 , located downstream, δ2 5 16.6 mm.

Evaluate the change in static pressure between sections 1

and 2 . Estimate the distance between the two sections.