Development of Stationary Disturbances in a Spatially Developing Jet

Nonmodal development of stationary three-dimensional disturbances in a circular jet is numerically investigated at the Reynolds number Re = 2850. The operating conditions of a laboratory experiment performed earlier in the Institute of Mechanics of Moscow State University are reproduced. A method for calculating optimal disturbances under the conditions of downstream developing main flow is developed. The disturbances associated with different azimuthal numbers are calculated. The shape, character of development, and growth degree of optimal disturbances are determined.