ИСТИНА

This study is dedicated to the investigation of the non-modal perturbation growth mechanism in a round submerged air jet. Experiments were conducted to excite the non-modal “lift-up” growth mechanism by introducing specific wave-like structures (deflectors) into the laminar submerged jet. It is demonstrated that the deflectors induce a vortex-like transverse motion, leading to the transition to turbulence (non-modal “lift-up” growth of introduced disturbances is identified), distinct from the modal mechanism. The evolution of disturbances in experiments qualitatively corresponds to the theoretically calculated optimal disturbances.