CFD modeling of heat transfer in turbulent pipe flows

Twelve versions of low Reynolds number k-epsilon and two low Reynolds numbe r Reynolds stress turbulence models for heat transfer were analyzed compara tively. Predictions of the mean axial temperature, the radial and axial tur bulent heat fluxes, and the effect of Prandtl number on Nusselt number were compared with the experimental data. The model by Lai and So from the k-ep silon group and Lai and So from the Reynolds stress group had the best over all predictive ability for heat transfer in turbulent pipe flow. The Lai an d So model was attributed to its success in the predictions of flow paramet ers such as mean axial velocity, turbulent kinetic energy, eddy diffusivity , and the overall energy dissipation rate. The k-epsilon models performed r elatively better than the Reynolds stress models for predicting the mean ax ial temperature and the Nusselt number. This qualitative and quantitative s tudy found the need for more sophisticated near-wall experimental measureme nts and the accuracy of the dissipation (of turbulent energy) and the press ure-scrambling models.