The far field of a submerged laminar jet: Linear hydrodynamic stability

A linear stability problem for a submerged Landau – Squire jet has been considered. It was shown that in the space, the intrinsic perturbation amplitude varied as a power function of the spherical radius R, read from the motion source. It was established that the increment in the sinusoidal disturbance became more than that for axisymmetric one for Re _D > 31. The linear stability theory was applied to the value of the laminar-turbulent transition coordinate as a function of the Reynolds number. A model criterion for a laminar-turbulent transition in the far jet region was proposed. For the first time, this made it possible to obtain a good agreement between the theoretical results and experimental data for Re_D < 2000.