Evaluate the rate of electrical heat dissipation

Question

Discus the following problem:

Q: Air at a static temperature of 70°F and a static pressure of 0.1 psia flows at zero angle of attack over a thin electrically heated flat plate at a velocity of 200 fps. If the plate is 4 in long in the direction of flow and 24 in. in the direction normal to the flow, determine the rate of electrical heat dissipation necessary to maintain the plate at an average temperature of 130°F.

GIVEN

High speed air flow over a heated flat plate

Air static temperature (TA) = 70°F

Air static pressure (P) = 0.1 psia

Air velocity (U_air) = 800 ft/s

Plate length (L) = 4 in = 1/3 ft

Plate width (w) = 24 in = 2 ft

Average plate temperature (Ts) = 130°F

ASSUMPTIONS

Steady state

Air behaves as an ideal gas

Air flows on one side of the plate only

Radiative heat transfer isnegligible