Solve the following problem:
Q: A stream of atmospheric air is used to dry a series of biological samples on plates that are each of length Li = 0.25 m in the direction of the airflow. The air is dry and at a temperature equal to that of the plates (T8 = Ts = 50°C). The air speed is u8 = 9.1 m/s.
(a) Sketch the variation of the local convection mass transfer coefficient hm,x with distance x from the leading edge. Indicate the specific nature of the x dependence.
(b) Which of the plates will dry the fastest? Calculate the drying rate per meter of width for this plate (kg/s · m).
(c) At what rate would heat have to be supplied to the fastest drying plate to maintain it at Ts = 50o during the drying process?
