Consider the flow of helium in a long rectangular microchannel, where the accommodation coefficients are The aspect ratio of the cross section of the microchannel is equal to 2. The microchannel...

Consider the flow of helium in a long rectangular microchannel, where the accommodation coefficients are
The aspect ratio of the cross section of the microchannel is equal to 2. The microchannel hydraulic diameter is 47 μm. 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.