Turbulence in subsonic jets in the Navier–Stokes solutions obtained with a 24th-order multi-operators-based scheme

Numerical solutions of the Navier–Stokes equations in the problem of subsonic jets obtained using a scheme with the 24th-order multi-operators-based dissipation-free approximations are presented and analysed. The spectral properties of the scheme obtained as a result of optimisation for high resolution of small solutions scales are described. The role of added multi-operators in excitation of instability, which make a 23rd-order contribution to the approximation error and form a dissipative component of the scheme, is studied. It is shown how well-known structures of jets with laminar regions of instability development, coherent structures and turbulent regimes at low and moderately high Reynolds numbers are displayed in numerical solutions. Comparisons with experimental data and results of calculations based on large-eddy simulations are given. The results of statistical processing with the calculation of autocorrelations are presented. In particular, their changes with distance from the nozzle are given, characterising different flow regimes at the considered Reynolds numbers. Comparison of spatial and temporal autocorrelations in the region of the turbulent regime indicate good fulfilment of Taylor’s hypothesis on frozen turbulence.