Numerical Investigation of Swirl Flow on Heat Transfer Enhancement in a Stepped Pipe

Abstract

AbstractIntroduction of swirling flow in pipes has significant impact in convective heat transfer applications. The swirl is induced by various means such as installing guide vanes and swirl generators along the pipe. In this work, a numerical study is performed to predict the influence of the swirl intensity on heat transfer. The numerical analysis is performed using a commercial Computational Fluid Dynamics package for turbulent flow with a Reynolds number around 3300. The intensity of the swirl component at the inlet of the pipe is varied from 0 to 5 m/s by having a constant axial component of 0.1 m/s. Moreover, a step is introduced on the inlet of the pipe and its influence in heat transfer is also investigated. The results revealed that the heat transfer takes place effectively when the diameter of the inlet pipe is smaller. However, it is less responsive for the induced swirl. Conversely, the heat transfer is not as effective as the diameter of the inlet is more. But it is highly sensitive for the swirl flows and the heat transfer could be enhanced by swirling flows where the inlet diameter is relatively high.KeywordsHeat transferSwirl flowAxisymmetric swirlCFDNumerical simulation