Heat transfer similarities between impinging jets and axial-flow impellers

Resumo

Similarities in the flow and heat transfer characteristics between simulation results of a round impinging jet and experimental data obtained on an agitated vessel with an axial flow impeller are presented in this paper. The electrodiffusion method was used in measuring the local heat transfer coefficients on a flat bottom of an agitated vessel. A small axial impeller has been built to provide a clearly defined flow imitating a submerged confined jet impinging the vessel bottom. Our simulation and experimental results show that the flow pattern in the impinging jet region below the axial flow impeller can be compared to the stagnation region of a round impinging jet with a corresponding tangential velocity component. CFD simulations of an impinging jet showed also the importance of different boundary conditions on small electrodes used with the electrodiffusion method and give an approximation of necessary correction factor.