| This work evaluates the capability of OpenFOAM (version 2206) to model a helical ovaltwisted tube heat exchanger under laminar flow conditions and compares the results with those
obtained using Star-CCM+. The study builds directly upon prior research presented in Laminar
Flow Heat Transfer in Helical Oval-Twisted Tube Heat Exchangers, with the primary objective
of validating OpenFOAM as an open-source alternative for simulating complex twisted helical
geometries.
Numerical simulations were conducted for both circular cross-section helical tubes and
oval-twisted helical tubes over Reynolds numbers ranging from 250 to 2000, with constant wall
temperatures of 320 K, 335 K, and 350 K and the inlet temperature of 300 K. The effects of
Reynolds number and wall temperature on the Nusselt number and pressure drop were evaluated.
Results at Tw = 350 K were directly compared with prior Star-CCM+ data for validation.
OpenFOAM successfully reproduced the trends observed in Star-CCM+, including the
consistent enhancement in heat transfer associated with the oval-twisted helical geometry. The
oval-twisted configuration showed a 25–42% increase in Nusselt number relative to the circular
helical tube across the Reynolds number range investigated. While higher pressure drops were
observed for the oval-twisted geometry, the thermal enhancement remained significant. While
there were discrepancies between different software packages, these were attributed primarily to
differences in mesh structure and numerical model.
These results demonstrate that OpenFOAM follows the same general trend as StarCCM+
but does deviate significantly at times when modeling heat transfer in circular and twisted helical
tube geometries.
Keywords: OpenFOAM, StarCCM+, heat exchanger, oval-twisted, CFD |