Abstract
In order to improve the performance of heat transfer with multiple impinging jet(MIJ), we investigate the DNS (direct numerical simulation) of four round impinging jet arranged at an inflow of flow field. From view of instantaneous vertical structures and time-averaged velocity distribution, it reveals that the generation of vortical structures in MIJ are enhanced due to an interaction between each jet and a peculiar upward flow compared to that of a single impinging jet(SIJ). In order to investigate dominant flow structures, DMD(dynamic mode decomposition) method is applied. It reveals that for SIJ large-scale structures which are formed over the impinging wall, are extracted with DMD, while for MIJ both peculiar structures around upward flow and large-scale structures similar to that of SIJ are extracted.
