-02- Problem 4. Boundary layer similarity (Chilton-Colbum analogy) A thin flat plate (0.2 m by 0.2 m) is oriented parallel to an T120C atmospheric airstream having a velocity of 40 ms. The air is at 4:40m a temperature of Tav = 20C. The air flows over the top and the 1..2010 -5-2015N bottom surfaces of the plate. An electric heating wire is placed plato inside the plate to maintain the plate at a constant temperature of T: = 120C. We are interested in knowing the energy input. Q. to the plate from the heater. Unfortunately, no watt meter is available to measure the electric power. A clever engineer suggested that you measure the drag force. FD, acting on the plate and use that information to estimate the energy input. Q. to the plate. a. If Fp = 0.075 N, estimate Q using the following properties for air at 70C., p =1.018 kgm. Co = 1009 Jkg K. Pr=0.70. v= 20.22*10^m's. (Ans: Q = 240 W] b. Discuss how and why Fo can be used to estimate Q. What are the restrictions (limitations) in using this approach