Thermal and flow interactions in rotor-stator Cavities: Enhancing cooling through multi-jet systems

This study examines the impact of air jets, rotor-stator spacing, and rotational speeds on flow characteristics and heat transfer in cooling systems of rotating machines, such as wind turbines. Building on previous work that explored various flow and jet configurations, this research employs both experimental and numerical methods to analyze a device composed of an aluminum rotor and stator. The spacing between the two components and the air jet parameters are variable, allowing for an in-depth investigation of the effects of these parameters on velocity profiles and flow patterns. More precisely, the analysis range extends from a rotational Reynolds number to , while varying the Reynolds number of the jet in a range from to . These Reynolds number ranges are selected to reflect realistic operational conditions in industrial applications, such as wind turbines and turbomachines, where rotational and jet speeds vary within these ranges. The chosen values ensure that both laminar and turbulent flow regimes are investigated, capturing the range of possible cooling scenarios encountered in practice. Numerical simulations are conducted with an optimized tetrahedral mesh to capture the details of turbulent flows. Boundary conditions include uniform velocity profiles and specific temperatures at the inlet and outlet of the simulation domain. A one-point statistical modeling approach with the Reynolds stress model is used to manage the complex interactions between the components of the turbulent flow. The results highlight that air jets are crucial for rotor cooling, with effects that vary according to the Reynolds number and significantly influence heat transfer. The research validates the effectiveness of the modeling methods and underscores the importance of a refined mesh to achieve accurate results. These findings provide valuable insights for optimizing cooling devices in various industrial applications, including turbomachines and wind turbines.