TY - JOUR

T1 - Small cluster formation in a free argon jet

AU - Bykov, N. Y.

AU - Fyodorov, S. A.

AU - Gorbachev, Yu E.

N1 - The research (the development of mathematical model of cluster formation in a free jet, problem setting and analysis) is funded by the Ministry of Science and Higher Education of the Russian Federation as a part of the World-class Research Center program: Advanced Digital Technologies (Contract No. 075-15-2022-311 April 20, 2022). The development of computation algorithm and computations is supported by the Russian Science Foundation, Project No. 22-11-00080, https://rscf.ru/project/22-11-00080/ . The computation resources were provided by the supercomputer center of Peter the Great St. Petersburg Polytechnical University.

PY - 2024/8/1

Y1 - 2024/8/1

N2 - A free argon jet flow accompanied by small clusters formation is studied with the direct simulation Monte Carlo method. Some near-continuum flow regimes characterized by Knudsen numbers in the 2 × 10 − 4 − 2 × 10 − 3 range are considered. A model for the argon clusters' growth/decay is proposed, taking into account the phase state of the clusters. The model consists of a chain of reactions leading to the clusters' formation, including the clusters' growth via triple/pair collisions of particles, and the clusters decay according to the collisional/unimolecular mechanism. The cluster size distributions in the jet far field are obtained. The results are compared with two experimental datasets. Good agreement is shown for most of the considered range of parameters. The triple particle collisions' influence on the argon clusters growth process is studied, and their important role in small cluster formation is demonstrated. It has been established that the cluster formation process is limited to an enough small spatial zone near the source outlet, of the order of several exit orifice diameters. The simulation shows a significant influence of cluster formation on the temperature and Mach number distributions, and a weak influence on the flow velocity. The formed clusters' translational temperatures and their velocities are close to the argon atoms' corresponding parameters. A non-equilibrium state, featured by a significant difference between the clusters' internal temperatures and the flow temperature, develops with distance from the source outlet.

AB - A free argon jet flow accompanied by small clusters formation is studied with the direct simulation Monte Carlo method. Some near-continuum flow regimes characterized by Knudsen numbers in the 2 × 10 − 4 − 2 × 10 − 3 range are considered. A model for the argon clusters' growth/decay is proposed, taking into account the phase state of the clusters. The model consists of a chain of reactions leading to the clusters' formation, including the clusters' growth via triple/pair collisions of particles, and the clusters decay according to the collisional/unimolecular mechanism. The cluster size distributions in the jet far field are obtained. The results are compared with two experimental datasets. Good agreement is shown for most of the considered range of parameters. The triple particle collisions' influence on the argon clusters growth process is studied, and their important role in small cluster formation is demonstrated. It has been established that the cluster formation process is limited to an enough small spatial zone near the source outlet, of the order of several exit orifice diameters. The simulation shows a significant influence of cluster formation on the temperature and Mach number distributions, and a weak influence on the flow velocity. The formed clusters' translational temperatures and their velocities are close to the argon atoms' corresponding parameters. A non-equilibrium state, featured by a significant difference between the clusters' internal temperatures and the flow temperature, develops with distance from the source outlet.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85201666743&origin=inward&txGid=9da8f3652afed8f6880482f831e06240

UR - https://www.mendeley.com/catalogue/f08c8fe4-2617-3a32-8378-1936be4daad2/

U2 - 10.1063/5.0222569

DO - 10.1063/5.0222569

M3 - Article

VL - 36

JO - Physics of Fluids

JF - Physics of Fluids

SN - 1070-6631

IS - 8

M1 - 087134

ER -