An aeroplane has a rectangular planform wing with a span of 12 m and a chord of 2 m. The aircraft is flying at cruising speed of 62 m/s at an altitude of 3,200 m. Assume that the skin-friction drag on the wing can be approximated by the drag on a flat plate of the same dimensions at 0° incidence. Calculate the skin-friction drag and the maximum boundary layer thickness assuming (i) a completely laminar flow, and (ii) a completely turbulent flow. Assume μ = 1.63.10-5 N s/m², p = 0.89 kg/m³. Then, calculate the skin-friction drag accounting for transition at Recr = 5.105. What would the drag benefit be if transition was delayed to a Reynolds number of 106? What reduction in a propeller engine power would this imply in the cruise condition, assuming a propeller efficiency of 0.88?

An aeroplane has a rectangular planform wing with a span of 12 m and a chord of 2 m. The aircraft is flying at cruising speed of 62 m/s at an altitude of 3,200 m. Assume that the skin-friction drag on the wing can be approximated by the drag on a flat plate of the same dimensions at 0° incidence. Calculate the skin-friction drag and the maximum boundary layer thickness assuming (i) a completely laminar flow, and (ii) a completely turbulent flow. Assume μ = 1.63.10-5 N s/m², p = 0.89 kg/m³. Then, calculate the skin-friction drag accounting for transition at Recr = 5.105. What would the drag benefit be if transition was delayed to a Reynolds number of 106? What reduction in a propeller engine power would this imply in the cruise condition, assuming a propeller efficiency of 0.88?

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.55P

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