Comparison of RANS, RSM, and IDDES Models for Swirling Turbulent Flow in a Pipe with a Short Twisted Tape

This study presents a comprehensive numerical investigation of fluid flow behavior within a pipe equipped with short twisted tape inserts using ANSYS Fluent. The primary objective is to evaluate the predictive accuracy of different turbulence modeling approaches, ranging from RANS to hybrid RANS-LES methods. Specifically, the performance of the Shear Stress Transport (k-omega SST), Reynolds Stress Model (RSM), and Improved Delayed Detached Eddy Simulation (IDDES) is compared. Given the complex swirling flow and secondary vortices generated by the short twisted tape, the numerical results are rigorously validated against experimental data. The comparative analysis demonstrates that while the SST model provides a computationally efficient estimation, the RSM and IDDES approaches offer superior accuracy in capturing the anisotropic nature of the turbulent stresses and the transient flow structures, respectively. Quantitative results reveal that the IDDES model exhibits the highest precision with an error margin of approximately ۵%, whereas the RSM and SST models show higher deviations of around ۱۱% and ۲۸%, respectively. These findings provide critical insights into the selection of the most reliable turbulence model for heat transfer enhancement devices in thermal engineering applications.

کلیدواژه ها:

Twisted tape ، Swirl flow ، Turbulent wake ، Numerical simulation ، Turbulence model