Mkwizu, M. HMatofali, A. XAinea, N2025-09-242025-09-2420182347-2529https://www.suaire.sua.ac.tz/handle/123456789/7026Journal articleThis work investigates the combined effects of thermophoresis, Brownian motion and variable viscosity on entropy generation in a transient generalized Couette flow of nanofluids with Navier slip and convective coolingof water-based nanofluids containing Copper (Cu) and Alumina (Al 2 O 3 ) as nanoparticles. Both first and second laws of thermody- namics are applied to analyse the problem. The nonlinear governing equations of continuity, momentum, energy and nanoparticles concentration are tackled numerically using a semi discretization finite difference method together with Runge-Kutta Fehlberg integration scheme. Numerical results for velocity, temperature, and nanoparticles con- centration profiles are obtained and utilised to compute the entropy generation rate, irreversibility ratio and Bejan number. Pertinent results are displayed graphically and discussed quantitatively.enNanofluids • Variable viscosity • Entropy generation • Bejan number • Thermophoresis • Brownian motionArticle