Impinging planar jets: hysteretic behaviour and origin of the self-sustained oscillations

摘要: The experimental and numerical investigation presented by Bertsch et al. (Phys. Rev. Fluids, vol. 5, 2020a, p. 054202) describes the self-sustained oscillations induced interaction of two impinging jets in microfluidic devices. While oscillatory regime interacting has been studied detail, physical mechanism behind these remains still undetermined. present paper focuses on two-dimensional oscillators subjected to a fully developed inlet flow, as contradistinction with Pawlowski (J. Fluid Mech., 551, 2006, pp. 117–139), who focused plug flow. linear global stability analysis performed confirms existence an oscillating mode, whose spatial structure qualitatively coincides that computed numerically 054202), suggesting from which would originate is predominantly two-dimensional. mode steady symmetry-breaking examined making use weakly nonlinear theory, shows how system exhibits hysteresis certain range aspect ratios. Lastly, sensitivity exploited identify wavemaker associated modes, examination allows us spot core instability at stagnation point Kelvin–Helmholtz instability, located region, main candidate for origin observed fluidic