# Asymmetric Magnetohydrodynamic Propulsion for Oil-Water Core Annular Flow Through Elbow
## 5 Conclusions  
In the present work, an asymmetrical magnetohydrodynamic (MHD) propulsion method is proposed to utilize the significant difference between the conductivity of heavy oil and an electrolyte solution to achieve the accelerating driving effect on the outer water ring. The differential MHD heavy oil flow model is built and used to simulate the flow state of the oil-water ring in the elbow under the combined action of the electric and magnetic fields. The electromagnetic and flow field simulation analysis results indicate that the Lorentzian magnetic force provided by the MHD field achieves the asymmetric acceleration of the oil-water rings to homogenize the water ring velocity on the inside and outside of  
Figure 7: Oil-water ring formation status under different pipeline outlets. (**a**) Outlet downward; (**b**) outlet upward; (**c**) outlet leftward; (**d**) outlet rightward. Red arrow: The flow direction of the oil-water ring.  
the elbows and push the deviated oil cores back to the center of the pipeline to repair the water film breakage. Additionally, the effects of parameters such as coil current, electrode plate voltage, and the conductivity of electrolyte solution on the stability of oil-water annular flow are investigated. The optimal parameter range of oil-water annular flow under the set parameters is obtained, and the reason for the rupture of the oil-water ring at the elbow below or above the optimal parameter range is clarified. Research exploring the impact of varying gravity directions reveals that the MHD method uniformly enhances the efficient transport of oil-water annular flows, particularly in complex terrain conditions, significantly boosting transport efficiency. This method not only overcomes the limitations of oil-water characteristics, transportation parameters, and other related parameters on oil-water annular flow transportation but also makes actual heavy oil transportation suitable for a wide range of complex terrain environments. This methodology can be further extended to be applied in the actual transportation process of various viscous oils and play an essential role in the future transportation of heavy oils.  
Conceptualization, C.W., Z.J. and W.Z.; methodology, W.Z. and Z.J.; software, Z.J., L.Y., Y.X. and J.Z.; validation, C.W. and Z.J.; formal analysis, Z.J.; investigation, Z.J., S.J., H.M. and R.S.; resources, C.W., B.L., E.L. and Y.L.; data curation, Z.J., L.Y. and Y.X.; writing--original draft preparation, Z.J.; writing--review and editing, C.W., W.Z., Z.J. and B.L.; visualization, C.W. and W.Z.; supervision, C.W., W.Z., Z.J., L.Y. and Y.L.; project administration, C.W. and W.Z.; funding acquisition, B.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China (nos. 22279118, 22279117, 22075254) and the Natural Science Foundation of Henan Province (242300421232).  
Not applicable.  
The data presented in this study are available upon request from the corresponding author.  
The authors declare no conflicts of interest.