“Numerical Research for the 2D Vorticity-Stream Function Formulation of the Navier-Stokes Equations and Its Application in Vortex Merging at High Reynolds Numbers”. CSIAM Transactions on Applied Mathematics, vol. 3, no. 2, May 2022, pp. 244-72, https://doi.org/10.4208/csiam-am.SO-2021-0015.