Glycerin is being heated by flowing between two very thin parallel 1-m-wide and 10-m-long plates with 12.5-mm spacing. The glycerin enters the parallel plates with a temperature 20°C and a mass flow rate of 0.7 kg/s. The outer surface of the parallel plates is subjected to hydrogen gas (an ideal gas at 1 atm) flow width-wise in parallel over the upper and lower surfaces of the two plates. The free-stream hydrogen gas has a velocity of 3 m/s and a temperature of 150°C. Determine the outlet mean temperature of the glycerin, the surface temperature of the parallel plates, and the total rate of heat transfer. Evaluate the properties for glycerin at 30°C and the properties of H₂ gas at 100°C. Are these good assumptions?

Transcribed Image Text:

H₂ gas flow 1 m -Glycerin flow Parallel plates