Effects of a turbulent wall jet over a non-confined backward-facing step

Experimental and numerical analysis of a turbulent wall jet downstream of a non-confined backward-facing step are presented. An infrared camera was used to visualize a temperature map of the heated plate downstream the step. A hot wire was utilized to measure the instantaneous local velocity and some PIV/SPIV measures were performed to obtain instantaneous two and three dimensional vector fields. The main objective was to visualize and compare both the fluid flow and the heat transfer, by studying the skin friction coefficient C_f and the Nusselt number Nu_d. The latter is obtained by the calculation of the heat transfer coefficient, evaluated by inverse method. Both experimental data and numerical approach provide good agreement regarding the flow structure and thermal data for measuring the position and the value of characteristics scales in the recirculation zone. Similarities and differences are highlighted in the paper compared to confined configurations.