Numerical investigation of fluid flow and heat transfer characteristics in multi-orifice synthetic jet structures

Traditional synthetic jet cooling structures typically locate the heat source outside the cavity and neglect the influence of side orifices. This design not only restricts heat dissipation performance but also leads to an overall larger size. To address these limitations, this study investigates three types of multi-orifice synthetic jet structures, with a particular focus on the characteristics of side orifices and the scenario where the heat source is positioned inside the cavity. Using finite element method to couple turbulence and heat transfer models, the performance of fluid flow and heat transfer in different jet structures is explored. Through the analysis of the average velocity variations at the orifices over a stable period and the pressure contours at representative time points, the airflow patterns of different jet structures are elucidated. Furthermore, the cooling characteristics of each jet structure are investigated by integrating temperature contours, average orifice temperatures, and heating boundary temperature variations and compared with those of traditional single-orifice structures. The results demonstrate that the Type 2 jet structure exhibits the most superior heat dissipation performance. Additionally, the effects of oscillation diaphragm amplitude and frequency on fluid flow and heat transfer performance in Type 2 structure are analyzed. This research provides valuable insights for designing multi-orifice synthetic jet structures with high-efficiency heat dissipation capabilities.