Analysis of Convective Heat Exchanges and Fluid Dynamics in the Air Gap of a Discoid Technology Rotary Machine

The proposed work focuses on the in-depth study of convective heat transfer in the unconfined air gap of a discoidal rotor-stator system. The rotary cooling mechanism is achieved by the injection of two air jets, while the cavity geometry is characterized by a dimensionless parameter G. The numerical analysis primarily concentrated on the effect of flow velocity and rotation on the heat exchange process. More precisely, the range of analysis extends from the rotational Reynolds number ${\text{Re}}_{\mathrm{\omega }}=2.35\times {10}^5$ to ${\text{Re}}_{\mathrm{\omega }}=5.04\times {10}^5$, while varying the Reynolds value of the jet in a range from $16\times {10}^3$ to $55.46\times {10}^3$. To carry out this analysis, a numerical simulation was conducted with Ansys-Fluent software, using the RSM turbulence model. The results of the study significantly reveal the impact of rotation on heat exchange transfer within the cavity, identifying two distinct zones of fluid recirculation. These zones exhibit remarkable heat transfer characteristics, contributing to a better understanding of the complex mechanisms governing heat transfer in this particular technological context. Additionally, the analysis of radial mean velocity distributions, as well as local and mean Nusselt numbers, provides further insight into the heat transfer performance of this unique configuration.