Thermodynamic performance of boehmite alumina nanoparticle shapes in the counterflow double pipe heat exchanger

Abstract

This work compares a theoretical model with a consolidated numerical model related to the thermodynamic performance of boehmite alumina nanoparticles in different formats in a counterflow double pipe heat exchanger. The shapes of the non-spherical nanoparticles under analysis are platelets, blades, cylindrical, and bricks. The second law of thermodynamics is applied to determine Nusselt number, pressure drop, thermal efficiency, thermal and viscous irreversibilities, Bejan number, and the out temperature of the hot fluid. The entropy generation rates associated with the temperature field and the viscous flow are graphical determined. The numerical model uses the k-ε turbulence model, which requires empirical factors to simulate turbulent viscosity and rate of generation of turbulent kinetic energy. Compatibility between the models was demonstrated. It was shown that the maximum absolute numerical error between the quantities Nusselt number, heat transfer rate, and pressure drop for established and specific conditions is less than 12.5 %.