Homework 7

# Homework 7 - b Calculate the thickness of the turbulent...

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AE 2020 LOW-SPEED AERODYNAMICS Assignment # 7 Please show your work. 1. a) Consider an airplane with an average (or characteristic) chord length of 10.4m. What is the free-stream Reynolds number for Mach 3 flight at an altitude of 20km? b) What is the characteristic free-stream Reynolds number of an airplane flying 160 mi/hr. in a standard sea-level environment? The average ( or characteristic) chord length is 4.0 ft. 2. A flat plate at zero angle of attack is mounted in a wind tunnel where 3 / 225 . 1 sec 5 10 7894 . 1 sec / 100 2 / 101325 m kg m kg m U m N P = - - × = = = ρ μ a) Using a transition criterion that 000 , 500 Re = tr x , how far from the leading edge (i.e. at what x location) does transition occur?
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Unformatted text preview: b) Calculate the thickness of the turbulent boundary layer at a point 1.0m from the leading edge. 3. Let us represent a rectangular wing of an airplane by a flat plate. The dimensions of the wing are chord=4 ft and span=28 ft and the motion is at standard sea level conditions. a) If the airplane is moving down the runway at 10 mph, what is the drag coefficient (due to skin friction) for the wing? b) If the airplane is moving down the runway at 10 mph, what is the total skin friction drag (in Newtons) acting on the wing? c) If the airplane is flying at 170 mph, what is the drag coefficient (due to skin friction) for the wing?...
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## This homework help was uploaded on 04/07/2008 for the course AE 2020 taught by Professor Ruffin during the Summer '07 term at Georgia Tech.

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