Turbulent forced convection and entropy analysis of a nanofluid through a 3D 90° elbow using a two‐phase approach

In a scenario characterized by a secondary flow called Dean's vortices, thermal and flow behavior analysis is examined. Forced convection of an Al 2 O 3 –water nanofluid through a three‐dimensional (3D) 90° elbow was analyzed numerically using a multiphase mixture model. Turbulence is taken into account by using the shear‐stress transport k – ω model. Also, entropy production is presented to obtain the optimized conditions. Simulation parameters consist of different Reynolds numbers (10,000100,000), nanoparticle volume fraction , nanoparticle diameter . The findings reveal that the increase in the and the Re along with a smaller d p discourages the appearance of Dean vortices in the flow. The pressure drop increases with the increase in the volume fraction and the decrease in the nanoparticles' diameter. The highest Nu M is observed at for . Significant heat transfer rates are observed near the outer wall. The minimum total entropy production is obtained at Re = 100,000 for and .