Roughness effect on the heat transfer and pressure loss performances of microscale tubes
and channels are investigated through a finite element CFD code. Surface roughness is explicitly
modelled through a set of random generated peaks along the ideal smooth surface. Different peak
shapes and distributions are considered; geometrical parameters are representative of tubes in the
diameter range from 50 to 150 μm. The use of a fine enough mesh allows the direct computation
of tube performances under the assumption of incompressible fully developed flow. As a result, a
significant increase in Poiseuille number is detected for all of the configurations considered, while
the effect of roughness on heat transfer rate is smaller and highly dependent on the tube shape.
