TY - JOUR

T1 - DSMC simulation of instability of plane supersonic jet in coflow

AU - Kashkovsky, A. V.

AU - Kudryavtsev, A. N.

AU - Shershnev, A. A.

N1 - This work was supported by the Russian Science Foundation, Project No. 18-11-00246. This support is gratefully acknowledged. The computational resources were kindly provided by the Equipment Sharing Center "Mechanics" of ITAM SB RAS and Siberian Supercomputer Center of the Institute of Computational Mathematics and Mathematical Geophysics SB RAS (sscc.ru)

PY - 2023/2/16

Y1 - 2023/2/16

N2 - The Direct Simulation Monte Carlo (DSMC) method is used for numerical simulation, at the molecular-kinetic level, of instability development in a plane supersonic jet exhausting into a coflow. The flowfields obtained in computations with a large number of test particles after their averaging over a small time interval almost coincide with the data of continuum simulations. The results show that sinuous instability is developed at subsonic convective Mach numbers, which means that disturbances of the antisymmetric mode are the most unstable ones. Typical nonlinear interactions of vortices are observed in the form of their roll-up around each other and pairwise merging. The mean velocity profiles reveal that mixing layers rapidly merge together, after which the jet velocity decreases and the jet width increases. By the end of the computational domain the velocity at the jet axis decreases approximately by a factor of 1.5, and the mean velocity profile becomes bell-shaped, which is typical for a developed jet flow. In the case of a supersonic convective Mach number, the sinuous instability corresponding to the antisymmetric mode is also excited. The structures formed in this case are sufficiently larger, and the jet breakup occurs at smaller distances from the nozzle exit. The flow dynamics is significantly affected by shock waves formed near vortices moving with a supersonic velocity with respect to the coflow.

AB - The Direct Simulation Monte Carlo (DSMC) method is used for numerical simulation, at the molecular-kinetic level, of instability development in a plane supersonic jet exhausting into a coflow. The flowfields obtained in computations with a large number of test particles after their averaging over a small time interval almost coincide with the data of continuum simulations. The results show that sinuous instability is developed at subsonic convective Mach numbers, which means that disturbances of the antisymmetric mode are the most unstable ones. Typical nonlinear interactions of vortices are observed in the form of their roll-up around each other and pairwise merging. The mean velocity profiles reveal that mixing layers rapidly merge together, after which the jet velocity decreases and the jet width increases. By the end of the computational domain the velocity at the jet axis decreases approximately by a factor of 1.5, and the mean velocity profile becomes bell-shaped, which is typical for a developed jet flow. In the case of a supersonic convective Mach number, the sinuous instability corresponding to the antisymmetric mode is also excited. The structures formed in this case are sufficiently larger, and the jet breakup occurs at smaller distances from the nozzle exit. The flow dynamics is significantly affected by shock waves formed near vortices moving with a supersonic velocity with respect to the coflow.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85149628897&origin=inward&txGid=6fac422674aa7634eb964b54253aba42

UR - https://www.mendeley.com/catalogue/7df608ca-8e1f-329c-8d8d-d4d643620bc4/

U2 - 10.1063/5.0132264

DO - 10.1063/5.0132264

M3 - Conference article

VL - 2504

JO - AIP Conference Proceedings

JF - AIP Conference Proceedings

SN - 0094-243X

IS - 1

M1 - 030087

T2 - 2021 Actual Problems of Continuum Mechanics: Experiment, Theory, and Applications

Y2 - 20 September 2021 through 24 September 2021

ER -