Hydrothermal Analysis of Pulsating SWCNT–water Nanofluid in a Triangular Corrugated Heat Channel: Comparative Study of Homogeneous Single-phase and Two-phase Eulerian–Lagrangian Models

Enhancing heat transfer performance in heated corrugated channels has become a main focus of investigation because of its crucial role in an extensive range of thermal systems. In the current study, a numerical investigation is carried out to examine the influence of laminar pulsating flow and SWCNT-water nanofluids on the flow behavior and heat transfer characteristics in a heat channel with nonequilateral triangle corrugations. Two different approaches are applied for nanoparticles motion such as homogenous single-phase model (HPM) and two-phase Eulerian–Lagrangian model (ELM). Governing equations are solved using the finite volume method. The computational fluid dynamics (CFD) simulations include Reynolds number, pulsation frequency and amplitude, volume concentration of SWCNT nanoparticles within the range of ۲۵۰≤ Re≤۱۲۵۰, ۱ ≤ f ≤ ۴, ۰.۵≤ A ≤ ۱, ۰% ≤φ≤ ۴% respectively.  According to results, it can be said that while increasing pulsation amplitude, A always yields higher mean Nusselt number, Numean and heat transfer enhancement ratio, η pulsating flow is more effective at lower pulsation frequencies, such as f=۰.۵ and Numean and η deteriorates with subsequent increment in f. For instance, at Re=۵۰۰, the mean Nusselt number increases from Numean=۱۳.۵۱۹ to Numean=۱۵.۲۸۲ when the pulsation amplitude is changed from A=۰.۵ to A=۰.۷۵ at f=۰.۵. This corresponds to a ۱۳.۰۴% enhancement in Numean. But this proportion is only observed as ۰.۳۷۸% increment in Numean for the change in pulsation amplitude from A=۰.۵ to A=۰.۷۵ at Re=۵۰۰ and f=۲. Furthermore, it was observed that Numean increases when the nanofluid model is changed from HPM to ELM especially at higher φ. At the optimal condition (Re = ۱۲۵۰, f = ۰.۵, A = ۱, φ = ۴%), Numean augmented by approximately ۸۸% with HPM and ۹۱% with ELM compared to the steady flow case, f=۰. The outcomes provide design insights for compact heat exchangers in applications such as microchannel coolers, automotive radiators, and electronic thermal management systems demonstrating that low pulsation frequencies and high pulsation amplitudes can remarkably improve heat transfer performance without changing exchanger dimensions.

کلیدواژه ها:

Computational fluid dynamics ، Corrugated channel ، Eulerian–Lagrangian model ، Heat transfer ، Pulsating nanofluid flow