Comments on "Optimization of entropy generation and dissipative nonlinear radiative Von Karman's swirling flow with Soret and Dufour effects"

The similarity variable (eta) is dependent only on z. From the energy and concentration equations, the temperature (T) and concentration (C) are dependent on r, z. Also, the temperature theta(eta) is dependent only on z whereas the other term is dependent on r, z. Thus, there is a contradiction between the 2 terms so that the temperature equation is invalid. In addition, the concentration phi(eta) is dependent only on z whereas the other term is dependent on r, z. Thus, there is a contradiction between the 2 terms so that the concentration equation is invalid. Furthermore, the R-g parameter in mass transfer irreversibility in the S-gen(''') expression is not defined. (C) 2020 Elsevier B.V. All rights reserved.