Multiple Jet Impingement - A Review

A review of the heat transfer characteristics of systems of multiple impinging air jets is presented. The objective is to provide a profound physical knowledge for the design of these impingement configurations, for which the factors that influence heat transfer are categorized and illustrated by exemplary results collated from different sources. In the course of the review, the flow and heat transfer characteristics of multiple impinging jets are introduced and compared to single impinging jets. Influencing factors on heat transfer are discussed, which include the effects of crossflow, jet Reynolds number, jet pattern, separation distance between a jet and target plate, and of the open area. An overview of the studies considering optimization and heat transfer enhancement is provided. In the review of numerical works, the suitability of the present CFD tools in predicting local heat transfer rates for multi-jet systems is discussed. Developments in the measurement technique and numerical accuracy are summarized. The review concludes with a summary and comparison of empirical correlations for both total average and locally resolved heat transfer coefficients.