Convection from multiple air jet impingement - A review

Abstract

• For S/D ≥ 3 and H/D = 2, the staggered pattern enhances Nu when compared with. • inline; • Wall motion is a topic of interest since even low velocities seem to enhance Nu; • Compressibility effects are important and Ma > 0.7 induces stronger instabilities; • SST k-ω model presents the best compromise between computational costs and. • accuracy. Multiple jet impingement is widely implemented in several industrial processes. The efficacy of this convective process depends on various parameters from the geometrical variables of the system, to the impinging surface roughness and the jet’s flow parameters. The study of this complex flow is challenging and increases with the confinement of the impinging domain. This work focus on a detailed analysis of confined and submerged multiple air jet impingement. To understand the physics under this process and the influence of the different variables on heat transfer performance, a review of the jet’s flow dynamics and heat transfer characteristics of submerged multiple air jet impingement systems is presented in this work. In this review, the parameters that affect the convective process are analyzed and special attention is given to less explored variables such as the surface configuration and motion, jet inclination and high jet temperature, and Mach number. The conclusions and relevant statements presented by several authors through their numerical and experimental works are presented and compared, to identify the values of each variable that enhance the heat transfer over the impinging surface. The numerical methods applied for the modeling of impinging jets are also analyzed. The advantages and disadvantages of each turbulence model discussed in the literature are presented and characterized in terms of their computational time and costs, in order to identify the most accurate for the multiple jet impingement process modeling. Finally, relevant correlations for the average Nusselt number, to characterize the heat transfer of single and multiple jet impingement are summarized.