Comparative Evaluation of Turbulence Models for Multi-Channel Heat Exchangers: Insights into Performance and Predictive Accuracy

Heat exchangers are very important in many varied industrial applications, including power generation, chemical processing, refrigeration, and automotive systems, since they enable effective heat transfer between two or more fluids, assuring maximum utilization of energy and stability in operations. Multi-channel heat exchangers are now coming into prominence due to their compact design and high thermal performance, which makes them well suited to applications where space and efficiency are key. In the present work, different turbulence models are comparatively evaluated for multi-channel heat exchangers. The aim is to identify the most appropriate model capable of capturing the complex phenomena of flow and heat transfer in such systems by comparing their performance and predictive capabilities. Due to the variations among turbulence models, namely k-ε RNG, k-ε Standard, k-ω SST, and k-ω Standard, differences in Nusselt numbers were observed within the Reynolds number range of ۵,۰۰۰ to ۱۰,۰۰۰. The highest Nusselt number, ۱۳۰.۴۰, was recorded at Re = ۱۰,۰۰۰ for the k-ε RNG model. This value shows a deviation of ۳۹.۱۶۴%, ۳۲.۶۳%, and ۳۷.۲۳% compared to the k-ε Standard, k-ω SST, and k-ω Standard models, respectively. Similarly, variations in the friction factor were observed across the Reynolds number range of ۵,۰۰۰ to ۱۰,۰۰۰, mirroring the trends seen in the Nusselt number. The highest friction factor, ۰.۱۸۵۷, was recorded for the k-ε RNG model at Re = ۵,۰۰۰. This value differs by ۷.۸۶%, ۱.۷۱%, and ۳.۶% compared to the k-ε Standard, k-ω SST, and k-ω Standard models, respectively.

Keywords:

Heat exchangers , heat transfer , flow turbulence enhancement , computational fluid dynamics , twisted tape.