DSMC Calculation of Free Jets through a Circular Orifice. Mach Disk and Barrel Shock by the DSMC Method.

Abstract The dynamics formation of a vapor jet with near-critical state parameters outflowing from a high-pressure vessel through a thin nozzle is studied. The numerical modeling of this process, by using a system of model equations for gas-vapor-liquid mixture, which include conservation laws of mass, momentum, and energy of phases in accordance with one-pressure, one-velocity and two-temperature approximations, was conducted, taking into account heat and mass transfer processes of evaporation and condensation under conditions of equilibrium state with modified reactingTwoPhaseEulerFoam solver of open package OpenFOAM. The process of barrel shock formation in supersonic boiling jet with shaping Mach disk is shown. It was found that the process of boiling fluid outflow is accompanied by formation of vortex zones near axis of symmetry and leads to generation of acoustic wave pulses series preceding the main jet flow, which are the source of pulsations, observed in experiments. The justification of applied numerical method reliability is shown by comparing the computational and analytical solutions for Sedov’s problem of a point explosion in gas-water mixture at the plane case.

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3D Calculation on a Supersonic Jet through a Circular Orifice : New Intermolecular Collision System of the DSMC Method

The Proceedings of Conference of Tokai Branch ◽

10.1299/jsmetokai.2004.53.345 ◽

2004 ◽

Vol 2004.53 (0) ◽

pp. 345-346

Author(s):

Masaru USAMI ◽

Koii TESHIMA

Keyword(s):

Supersonic Jet ◽

Collision System ◽

Dsmc Method ◽

Circular Orifice ◽

Intermolecular Collision

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Molecular Simulation of Rarefied Supersonic Free Jets by DSMC Method.

JSME International Journal Series B ◽

10.1299/jsmeb.42.369 ◽

1999 ◽

Vol 42 (3) ◽

pp. 369-376 ◽

Cited By ~ 12

Author(s):

Masaru USAMI ◽

Koji TESHIMA

Keyword(s):

Molecular Simulation ◽

Dsmc Method ◽

Free Jets

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Parallel DSMC Simulation of a Single Under-Expanded Free Orifice Jet From Transition to Near-Continuum Regime

Journal of Fluids Engineering ◽

10.1115/1.2062807 ◽

2005 ◽

Vol 127 (6) ◽

pp. 1161-1170 ◽

Cited By ~ 10

Author(s):

J.-S. Wu ◽

S.-Y. Chou ◽

U.-M. Lee ◽

Y.-L. Shao ◽

Y.-Y. Lian

Keyword(s):

Flow Structure ◽

Three Dimensional ◽

Direct Simulation Monte Carlo ◽

Mean Free Path ◽

Mach Disk ◽

Orifice Diameter ◽

Axial Distance ◽

Free Jet ◽

Barrel Shock ◽

Dynamic Domain Decomposition

This paper describes the numerical analysis of the flow structure of a single underexpanded argon free jet issuing into a lower-pressure or vacuum environment using the parallel three-dimensional direct simulation Monte Carlo (DSMC) method employing dynamic domain decomposition. Unstructured and tetrahedral solution-based refined mesh depending on the local mean free path is used to improve the resolution of solution. Simulated Knudsen numbers of the stagnation conditions based on orifice diameter, Reynolds numbers based on the conditions at the orifice exit, and stagnation-to-background pressure ratios are in the range of 0.0005–0.1, 7–1472, and 5-∞, respectively, where “∞” represents vacuum condition in the background environment. Results show that centerline density decays in a rate proportional to the inverse of the square of the axial distance (z−2) from the orifice for all ranges of flow in the current study. The more rarefied the background condition is, the longer the z−2-regime is. In addition, a distinct flow structure, including barrel shock, Mach disk and jet boundary, is clearly identified as the Knudsen number reaches as low as 0.001. Predicted location and size of Mach disk in the near-continuum limit (Kn=0.001,0.0005) are found to be in reasonable agreement with experimental results in the continuum regime.

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Experimental and numerical investigation of an axisymmetric supersonic jet

Journal of Fluid Mechanics ◽

10.1017/s0022112000002329 ◽

2001 ◽

Vol 426 ◽

pp. 177-197 ◽

Cited By ~ 43

Author(s):

B. MATÉ ◽

I. A. GRAUR ◽

T. ELIZAROVA ◽

I. CHIROKOV ◽

G. TEJEDA ◽

...

Keyword(s):

Rotational Temperature ◽

Supersonic Jet ◽

High Sensitivity ◽

Mach Disk ◽

Low Velocity ◽

Barrel Shock ◽

Global Agreement ◽

Temperature Maps ◽

Subsonic Region ◽

Subsonic Part

A comprehensive study of a steady axisymmetric supersonic jet of CO2, including experiment, theory, and numerical calculation, is presented. The experimental part, based on high-sensitivity Raman spectroscopy mapping, provides absolute density and rotational temperature maps covering the significant regions of the jet: the zone of silence, barrel shock, Mach disk, and subsonic region beyond the Mach disk. The interpretation is based on the quasi-gasdynamic (QGD) system of equations, and its generalization (QGDR) considering the translational–rotational breakdown of thermal equilibrium. QGD and QGDR systems of equations are solved numerically in terms of a finite-difference algorithm with the steady state attained as the limit of a time-evolving process. Numerical results show a good global agreement with experiment, and provide information on those quantities not measured in the experiment, like velocity field, Mach numbers, and pressures. According to the calculation the subsonic part of the jet, downstream of the Mach disk, encloses a low-velocity recirculation vortex ring.

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