... of 600–1600, and correlations for the j and f-factor of the IFWF are proposed using the responses surface method. The parametric study of the contribution ratio on the j-factor, f-factor, and JF-factor is obtained by the Taguchi method, including 18 cases with different combinations of key parameters...

... decrease with increasing the Hartmann number especially at its lower values. Furthermore, response surface method is adopted to find the optimal location of the elliptic cylinder. Response surface optimization results reveal that the average Nusselt number shows a decreasing–increasing trend...

... width ratio ( 0.7 < b / D < 0.9 ) , cross-cut length ratio ( 2 < s / D < 2.5 ) , and twist ratio ( 2 < y / D < 4 ) . The objective functions are the Nusselt number ratio ( Nu / Nu s ) , the friction factor ratio ( f / f s ) , and the thermal performance ( η ) . Response surface method...