Entropy generation in dissipative flow of Williamson fluid between two rotating disks

This communication addresses flow characteristics of Williamson fluid between two rotating disks. Electrically conducting fluid is considered. Total entropy generation rate is calculated through implementation of second law of thermodynamics. The lower and upper disks have different stretching rates and angular velocities for rotation. Characteristics of heat transport are expressed through dissipation, heat generation/absorption and thermal radiation. Von Karman transformations are utilized to convert the dimensional flow expressions into dimensionless form. Convergent series solutions are constructed. Influence of different pertinent variables on velocity, temperature, entropy number, skin friction coefficients and Nusselt numbers are studied. It is observed that the axial and tangential velocities increase for higher Weissenberg number while radial velocity decays. Further entropy number remarkably increases for magnetic, radiation and Brinkman number. Bejan number is less for higher magnetic parameter, stretching parameter, Brinkman number and Weissenberg number. (C) 2018 Elsevier Ltd. All rights reserved.