Response surface technique for time-dependent Carreau nanofluid flow with entropy generation: A statistical modelling

Optimizing the heat transfer rate for the flow of fluid is fruitful for the industries as well as in the biomedical field. The current study is focused on statistical analysis of heat transmission of the Carreau nanofluid flow by the inclusion of the responses in terms of Nusselt number through response surface methodology. Nonlinear mixed convection is considered to study the natural as well as forced convection. Cattaneo-Christov heat transmission model is employed along with heat generation. Also, entropy generation is considered to analyze the amount of heat disorder in the flow system. After modelling the problem through mathematical expressions, graphs of solutions have been obtained. Results demonstrated that the lower skin friction for higher unsteadiness parameter while keeping the mixed convection factor at its lowest value. Larger rate of heat transmission is obtained for higher value of the thermal relaxation parameter when the unsteadiness parameter is kept low. The Nusselt number decreases by 8-10 % for increasing unsteadiness parameter. Heat dissipation parameter show negative sensitivity at low, medium and high level of Eckert number and positive sensitivity is exhibited by thermal relaxation parameter. For the experimental setup by response surface methodology, the better correlation coefficient is 100 % attained.