Experimental Study of Compressible and Incompressible Micro-scale Jet Impingement Heat Transfer

다국어 초록 (Multilingual Abstract)

The heat transfer characteristics of an unconfined slot air jet for compressible and incompressible flow impinging on a heated flat plate have been investigated experimentally. The influence of the Reynolds number and the nozzle-to-plate spacing on the Nusselt number was studied. The variable parameters in the experiment were a jet width (0.25 ㎜), the Reynolds number (150~5000), the dimensionless nozzle-to-plate spacing (Z/B = 1~20). The results showed that the thermal characteristics of the micro-scale impinging jet are similar to those of the macro-scale impinging jet. At a low Reynolds number of Re s 2500, (1) the heat transfer distribution for nozzle-to-plate spacing was observed non-monotonic behavior which has a peak due to the opposite influences of turbulence intensity and diminished jet velocity, (2) the turbulence intensity peak moves from Z/B = 12 to 3 with increasing the Reynolds number. At a high Reynolds number of Re ~ 3250, (3) the maximum heat transfer occurs at Z/B = 3 due to the turbulence intensity and compressibility of jet air.

목차 (Table of Contents)

• Abstract
• 1. Introduction
• 2. Experimental apparatus and procedures
• 3. Data analysis and reduction
• 4. Results and discussion
• 5. Conclusion
• Acknowledgement
• Reference