Numerical investigation on the fluid flow and heat transfer of non-Newtonian multiple impinging jets

• Impingement of power-law multiple jets on a plate has been studied numerically.
• Decreasing the jet-to-plate spacing decreases the size of entrainment vortices.
• For a given Reynolds number, higher power-law index leads to higher Nusselt number.

Laminar power-law non-Newtonian fluid flow and heat transfer characteristics of multiple impinging square jets have been studied, numerically. The effect of inlet Reynolds number, jet-to-plate spacing and fluid power-law index on the flow structure and wall Nusselt number has been investigated. Numerical results have been presented for Reynolds numbers 100, 200, power-law indices 0.4–1.6 and dimensionless jet-to-plate spacings 0.25–1.0. Results showed that for a given Reynolds number and consistency coefficient, increasing of the power-law index leads to the higher impingement velocity and higher wall Nusselt number. For higher jet-to-plate spacings, the peripheral entrainment vortices are created around the jet body and by decreasing the spacing, these vortices disappear. Furthermore, the numerical results showed that decreasing of jet-to-plate spacing increases the wall Nusselt number.