The surface temperature of a thin flat plate located parallel to an air stream is 90?C. The free stream velocity is 60 m/s and the temperature of the air is 0?C. The plate is 60 cm wide and 45 cm long in the direction of the air stream. Neglecting the end effect of the plate and assuming that the flow in the boundary layer changes abruptly from laminar to turbulent at a transition Reynolds number of Retr = 4 × 105, find(a) the average heat transfer coefficient in the laminar and turbulent regions(b) the rate of heat transfer for the entire plate, considering both sides(c) the average friction coefficient in the laminar and turbulent regions(d) the total drag forceAlso plot the heat transfer coefficient and local friction coefficient as a function of the distance from the leading edge of the plate.GIVENAir flow over a flat platePlate surface temperature (Ts) = 90?CAir velocity (U??) = 60 m/sAir temperature (T??) = 0?CPlate length (L) = 45 cm = 0.45 mPlate width = 60 cm = 0.6 mASSUMPTIONSSteady stateEnd effect of the plate is negligibleBoundary layer changes from laminar to turbulent at Re = 4 ×105

Transcribed Image Text:

Alr 60 m/s 0°C 90°C 60 cm 45 cm