Thermal Performance Analysis of Twin Pulsating Turbulent Jets Impinging over Intermittently Moving Plate

This study introduces a novel approach to enhance the thermal performance of a confined slot jet impingement system over a heated plate using multiple pulsating jets. By analyzing the complex fluid flow structure and transport phenomena, resulting from the interaction of the twin jets with the target surface, this research highlights three crucial factors: jet pulsation frequency, phase difference, and intermittent motion of the impingement plate. These factors disrupt the boundary layer, create favorable temperature and velocity gradients, and improve heat transfer rates. The velocity vector field analysis reveals the generation of vortices in multiple regions due to the coherent pulsatile jet. The study concludes that increasing the jet pulsation frequency beyond the critical value corresponding to a Strouhal number = 0.26 improves heat removal rate from the isothermal plate. Interestingly, the phase difference promotes heat transport only when the plate is stationary but loses its beneficial effect during intermittent motion. Phase difference results in a 6.7% improvement in average Nusselt number at a jet pulsation frequency of 40 Hz with a stationary plate, particularly benefiting lower frequency pulsating flows. Non-uniform plate motion exhibits the strongest influence on the heat transfer process among the investigated factors. Optimal thermal energy exchange requires careful adjustment of these factors. For instance, when both jet pulsation and intermittent plate motion frequencies are set to 100 Hz, convective heat transfer improves by up to 48% compared to the steady-state scenario, regardless of the phase difference. These findings may benefit the design and optimization of jet impingement-based thermal management systems.

Automated summary

This study introduces a novel approach to enhance the thermal performance of a confined slot jet impingement system. The research highlights the importance of jet pulsation frequency, phase difference, and intermittent motion of the impingement plate in improving heat transfer rates. The findings may benefit the design and optimization of jet impingement-based thermal management systems.