In this paper, the two-phase mixture model is used to determine the influence
of the number of ribs on the first-law and second-law performance
features of the laminar forced convection flow of a biologically prepared
silver/water-ethylene glycol nano-fluid (NF) in a rifled tube. The influence of
the Reynolds number (Re), nanoparticle concentrations (φ) on the outcomes
are also evaluated. Two parameters of Performance Evaluation Criterion (PEC)
and Figure of Merit (FOM) are defined to analyze the merit of using rifled tube
and NF over the plain tube and water-ethylene glycol mixture (50:50 by
volume) for the same Re and φ. The results showed that the increase in the
number of ribs is desirable from the first-law viewpoint and undesirable from
the second-law viewpoint. It was found that for all the examined cases, the
hydrothermal performance of the rifled tube is always better than the plain
tube, and boosting the Re and decreasing the φ leads to an increase in FOM.
Moreover, it was observed that the PEC for the six-head and eight-head rifled
tubes is always greater than unity and for the two-head rifled tube is always
less than unity.