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Obtaining uniform cooling on a hot surface by a novel swinging slot impinging jet

Bijarchi, M. A ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1016/j.applthermaleng.2019.01.037
  3. Publisher: Elsevier Ltd , 2019
  4. Abstract:
  5. In this study, a novel 2D laminar Swinging Slot Impinging Jet (SSIJ) on a heated flat surface was investigated using numerical simulation. The impinging jet was introduced to improve the uniform cooling of a hot surface while enhancing the heat transfer rate by disrupting the boundary layer. The impinging jet moves along the target surface similar to the swinging motion of a pendulum. The effects of Reynolds number, dimensionless jet to target distance, maximum angle of swinging, and frequency of jet oscillations were studied, and physics of the new impinging jet were fully discussed. Lastly, optimization was undertaken to search for the optimal variables leading to uniform heat fluxes. A combination of pattern search and gradient-based methods was used to minimize the root mean square of the difference between the local Nusselt number and a target uniform Nusselt distribution. To achieve uniform cooling, 15 cases were investigated (5 Nusselt numbers and 3 nozzle to target surface ratios). It was found that for the nozzle to target surface ratios of 0.5 and 0.35, SSIJ was remarkably successful to accomplish uniform cooling for all Nusselt numbers. © 2019 Elsevier Ltd
  6. Keywords:
  7. Slot impinging jet ; Uniform cooling ; Boundary layers ; Nozzles ; Nusselt number ; Optimization ; Reynolds number ; Gradient-based method ; Heat transfer rate ; Local Nusselt number ; Nusselt distribution ; Optimal variables ; Pattern search method ; Slot impinging jets ; Uniform heat flux ; Cooling
  8. Source: Applied Thermal Engineering ; Volume 150 , 2019 , Pages 781-790 ; 13594311 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S1359431118340456