PROBLEM 3

Problem 13.29 Consider the flow of helium in a long circular microchannel, where the accommodation

coefficients are a =a=0.85. The microchannel hydraulic diameter is 40 um. At a location where

pressure is equal to 1.2 bars, the Mach number representing the mean helium velocity is equal to 0.02 and

the mean fluid temperature is equal to 310 K. Calculate the frictional pressure gradient, and the local heat

transfer coefficient assuming a uniform wall heat flux boundary condition.