This study investigated the boiling heat transfer characteristics of three upward circular water jets impinging on a hot moving steel sheet, with a specific focus on the interference effects between adjacent jets. Although run-out table(ROT) cooling is a key technology in thermomechanically controlled processing(TMCP), the quantitative understanding of multiple-jet cooling remains limited. Experiments were conducted using a heated stainless-steel sheet with an initial temperature ranging from 250 to 550°C and a conveying velocity of 4.4 m/s. Three 7-mm diameter nozzles were arranged in the width direction of the sheet with nozzle spacings of 15 and 21 mm. The surface heat flux distribution was evaluated using an inverse heat conduction analysis based on temperature data measured using an infrared camera. High-speed imaging revealed that flow collisions between adjacent jets formed vertical water films, restricting the effective cooling area of the central jet. However, the relationship between the maximum heat flux and local surface temperature is consistent with existing correlations for single jets. These findings highlight that the experimental data for single jets can be used to approximately predict the heat removal for multiple jets.
Hikata et al. (Thu,) studied this question.