The water heats up as it flows through a stack of parallel metal blades. The sheet-to-sheet spacing is D = 1 cm and the average velocity through each channel is V = 3.2 cm/s. Each blade is electrically heated so that the two sides of the blade together release 1600 W/m2 in water. Assuming that the properties of water can be evaluated at 50°C and that the flow is thermally fully developed:
(a) Verify that the flow is laminar.
(b) Calculate the mean temperature difference between the blade and the water jet.
(c) Calculate the rate of temperature rise along the channel.
(d) Show how long the channel must be for the assumption that the flow is
fully thermally developed