NUMERICAL ANALYSIS OF THE INFLUENCE OF THE JET-TO-JET SPACING BETWEEN TWO ADJACENT AIR JETS IMPINGING A FLAT PLATE

Jet impingement is a technology widely implemented in industrial processes since it ensures high heat transfer rates and a uniform distribution of temperatures over the target surface. These characteristics can be extremely advantageous in some applications such as reflow soldering. Considering that the performance of the heat transfer through multiple jet impingement is govern by jets interactions (jet-to-plate distance, jet-to-jet spacing, etc.), fluid flow parameters (Reynolds number, jet temperature) and geometry of the target surface, it is extremely important to perform an in-depth study to understand the influence of these parameters. To minimize the number of experiments required to conduct this study, numerical simulation has been a tool widely implemented in industrial and academic research. In that sense, this paper presents an analysis of the behavior of air jets impinging a flat plate, using the CFD software ANSYS FLUENT. To ensure the reliability of the results, a preliminary analysis using a single jet was conducted. A grid independence analysis was conducted, and three turbulence models (SST k-omega, k-omega and k-epsilon) were implemented in order to determine the one that presents a higher accuracy. This study is the starting point for the analysis of the interaction between two adjacent air jets, considering a Reynolds number of 2,000 and a jet-to-plate distance (H/D) of 7. The results emphasize the importance of the jet-to-jet spacing in the heat transfer performance of multiple jet impingement, being important to determine the optimized value for a specific application.