The thermo-hydraulic and exergetic analysis of innovative vortex generator designs in a circular tube: A GEKO-based CFD approach
International Journal of Thermal Sciences, vol.229, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 229
- Publication Date: 2026
- Doi Number: 10.1016/j.ijthermalsci.2026.111131
- Journal Name: International Journal of Thermal Sciences
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Keywords: Exergetic analysis, GEKO turbulence model, Heat transfer enhancement, Numerical analysis, Thermo-hydraulic performance, Vortex generator
- Yozgat Bozok University Affiliated: Yes
Abstract
This study presents a numerical investigation of the thermo-hydraulic performance and exergy destruction of five innovative Vortex Generator (VG) configurations in a circular tube subjected to a uniform heat flux boundary condition over a Reynolds number range of 5000–20000. A key methodological contribution of this work is the application and calibration of the GEneralized K–Omega (GEKO) turbulence model for accurately capturing the vortex-induced flow structures in internal flows. Accordingly, a comprehensive computational evaluation is performed to assess the predictive performance of the GEKO turbulence model in turbulent flows, both with and without vortex-induced flow structures, at both macroscale and local level, while systematically benchmarking its accuracy against experimental data and widely used conventional RANS-based turbulence models. Following calibration at C SEP = 2.25, the GEKO model provides the closest agreement with experiments and exceeds RANS-based models in predicting Nusselt number and friction factor. A local-level validation of periodically ribbed turbulent flow in a rectangular duct at Re = 15000 demonstrates high predictive accuracy, which further reinforces the reliability and robustness of the GEKO model. Moreover, the comparative assessment indicates that the Novel Inclined Delta Winglet (NIDW) configuration outperforms other designs, providing enhanced heat transfer with moderate pressure drop, achieving a maximum Thermal Enhancement Factor of 1.3 at Re = 5000. Furthermore, second-law analysis demonstrates that all VGs reduce total system irreversibility (N s < 1) by effectively compensating for hydrodynamic penalties with enhanced thermal mixing. Correspondingly, evaluations of the Bejan number and exergetic efficiency identify the NIDW as the most effective design for minimizing exergy destruction.