TY - JOUR
TI - Swirl development and enhanced heat transfer analysis of ferrofluid in elliptical ducts under thermal-magnetic-flow fields coupling
AU - Wang Cuihu
AU - Zhang Wenquan
AU - Rong Duo
AU - Jia Zepeng
AU - Gong Bin
AU - Wu Jianhua
JN - Thermal Science
PY - 2024
VL - 28
IS - 2
SP - 1677
EP - 1688
PT - Article
AB - It is a new practical method to apply external magnetic field in magnetic  working fluid to enhance heat transfer. In this paper, the swirl flow and  heat transfer characteristics of ferrofluid in elliptical tubes under  thermal-magnetic-flow fields coupling have been studied by using the finite  volume method. The flow structure and secondary vortices evolution process  of magnetic nanofluid in elliptical ducts under the action of the magnetic  fields have been obtained. The effects of magnetic induction intensity and  the ratio of major axis to minor axis of elliptical pipe on the flow and  heat transfer performances have been main investigated. The results show  that there is obvious secondary flow (with four vortices or eight vortices)  on the cross section and the swirling flow is gradually formed due to the  coupling of thermal-magnetic-velocity fields. With the increase of the ratio  of major axis to minor axis, the heat transfer enhancement effect with the  application of external magnetic field is weakened. The comprehensive  performance of flow and heat transfer are better at lower Reynolds number  and higher magnetic induction intensity.