This study investigates flow and heat transfer characteristics of two-dimensional impinging twin jets with plate spacing ratios H/w=8.0 and 5.0. Simultaneous PIV and two-color LIF measurements were conducted with a jet-to-ambient temperature difference of 10 K. For H/w=8.0, periodic vortex shedding induced jet oscillation with a dominant frequency of 16.9 Hz, and momentum transport was governed by the inner shear layer. In contrast, H/w=5.0 exhibited irregular vortices in the recirculation region, leading to enhanced turbulent heat flux. These results highlight the strong dependence of mixing and heat transport on plate spacing ratio.
Koyama et al. (Wed,) studied this question.