**4. Conclusions**

In this study, OpenFoam was employed to analyze the velocity, the temperature, the wall shear stress in the main trough of a blast furnace and the influence of different tap hole angles on the main trough. Some conclusions are highlighted as follows.


**Author Contributions:** Y.G. is responsible for writing the article and simulation calculation of blast furnace main trough. M.L. is responsible for the guidance of code writing in simulation. H.W. is responsible for the language and format of the article. D.L. and X.W. provide blast furnace main trough data involved in the simulation process. Y.Y. guide the overall direction of the article, provide simulation technical guidance and simulation equipment. All authors have read and agreed to the published version of the manuscript.

**Funding:** We gratefully acknowledge financial support from the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning (No.TP2015039), National Natural Science Foundation of China (No.51974182), National 111 project, Grant/Award No. 17002 and Laiwu Steel. The simulations and analyses were completed using OpenFoam open source.

**Conflicts of Interest:** The authors declare no conflict of interest.
