Problem 2: You are designing a heated flat plate for an experiment in my wind tunnel. Air at 27°C and 20m/s flows over the plate, which is kept at a constant temperature of 77°C by internal heaters. A small wire trips the boundary laver so that it is fully turbulent at the start of the plate (x=0). (a) Determine how long the plate should be to achieve a velocity boundary layer thickness of 40 mm at the end of the plate. Ans: 2.0 m (b) How much heat needs to be supplied to the plate, if it is 1.2 m wide? (c) What is the total drag force on the plate? Ans: 1.66 N

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