Features of heat transfer at interaction of an impact swirl jet with a dimple

Abstract

Experimental results on investigation of heat transfer at interaction of an air impact jet with a semi-spherical cavity are presented in this work. This research is continuation of investigations of turbulent jet interaction with complex surfaces and search for the method of heat transfer control. Experiments were carried out with fixed geometry of a semi-spherical cavity (D C = 46 mm) and swirl parameter (R = 0; 0.58; 1.0; 2.74). The distance between the axisymmetric nozzle and obstacle was 2-10 sizes over the nozzle diameter, and the Reynolds number, Re 0 , varied within 1 to 6•10 4. It was found out that with an increase in swirling heat transfer intensity decreases due to fast mixing of the jet with ambient medium. In general, the pattern of swirl jet interaction with a concave surface is complex and multifactor.

Heat transfer in a confined impinging jet with swirling velocity component

“…A large drop in Nusselt number values is visible at the center of the stagnation region which is a consequence of small values of the axial velocity components there. It is in accord with some of the literature data [6], even though as pointed out by [7], the flow and heat transfer characteristics show drastically different results depending on the type of swirl generators. In our case, we have used an axialflow impeller with six blades, 45…”