Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 07, 2019 - November 08, 2019
In order to improve the heat transfer performance of a single impinging jet, multiple impinging jets in which multiple jets are arranged are used. However, the multiple impinging jets has a problem in that the heat transfer characteristics become non-uniform because adjacent jets form a complicated flow field with each other. Therefore, in this paper, in the multiple impinging jet, control is performed to give oscillation to all the nozzles in the row direction at a sin cycle. And it investigated about the influence of the oscillation on the flow structure and heat transfer characteristic of a multiple impinging jets using DNS (direct numerical simulation). In the time-averaged velocity contour, the wall jet spreads in the oscillating direction under all conditions. In addition, strong wall jets were observed when oscillation was applied. The time-averaged Nusselt number contour shows high values near the impinging point under all conditions, and the Nusselt number decreases as going from the impinging point toward the outside of the calculation area. From the RMS value of Nusselt number at each frequency for evaluating the uniformity of the Nusselt number, the uniformity of the Nusselt number was improved by performing oscillation control.
