Air flowing through a tube of 75-mm diameter passes over a 150-mm-long roughened section that is constructed from naphthalene having the properties -4 flow rate and the average mixed outlet temperature to analyze the performance of the average (50 µ,m) diameter channel and concludes that flow rates and heat transfer coefficients are increased and decreased, respectively, by about 5% when forced convection occurs in microchannels. M = 128.16 kg/kmol and psat(300 K) = 1.31 X 10 bar.
Comment on the validity of the experimentalist's conclusion.