LES investigation of real-fluid effect on underexpanded jets

Abstract The shock-structure and the related acoustic field of underexpanded jets undergoes significant changes as the Mach number Mj is increased. The present investigation is carried out to study the effect of Mach number on an underexpanded 2:1 elliptic-slot jet. Experimental data are presented for fully expanded Mach numbers ranging from 1.3 to 2.0. It is observed that the ‘cross-over’ point at the end of the first cell at low Mach numbers gets replaced by a normal shock at a highly underexpanded condition resulting in the formation of a ‘barrel’ shock along the minor-axis side with a ‘bulb’ shock formed along the major-axis side. The above change in shock structure is accompanied by a related change in the acoustic field. The amplitude of fundamental frequency along the minor-axis side grows with Mj but falls beyond Mj = 1.75. Along the major-axis side, however, the fundamental frequency does not exist at low Mach numbers. It appears at Mj = 1.75 but then falls at Mj = 2.0. The related azimuthal directivity of overall noise levels (OASPL) shows significant changes with Mj.

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Influence of Real-Fluid Properties in Modeling Decompression Wave Interacting with Ductile Fracture Propagation

Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles ◽

10.2516/ogst:2005050 ◽

2005 ◽

Vol 60 (4) ◽

pp. 711-719 ◽

Cited By ~ 9

Author(s):

A. Terenzi

Keyword(s):

Ductile Fracture ◽

Fracture Propagation ◽

Real Fluid ◽

Decompression Wave ◽

Fluid Properties

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NUMERICAL SIMULATION OF 2D LIQUID SLOSHING

International Journal of Applied Mechanics ◽

10.1142/s1758825112500147 ◽

2012 ◽

Vol 04 (02) ◽

pp. 1250014 ◽

Cited By ~ 1

Author(s):

LI CAI ◽

JUN ZHOU ◽

FENGQI ZHOU ◽

WENXIAN XIE ◽

YUFENG NIE

Keyword(s):

Kinematic Viscosity ◽

Numerical Experiments ◽

Viscous Fluids ◽

Liquid Sloshing ◽

Ghost Fluid Method ◽

Weighted Essentially Nonoscillatory ◽

Level Set Function ◽

Real Fluid ◽

Set Function

In this paper, we present an extended ghost fluid method (GFM) for computations of liquid sloshing in incompressible multifluids consisting of inviscid and viscous regions. That is, the sloshing interface between inviscid and viscous fluids is tracked by the zero contour of a level set function and the appropriate sloshing interface conditions are captured by defining ghost fluids that have the velocities and pressure of the real fluid at each point while fixing the density and the kinematic viscosity of the other fluid. Meanwhile, a second order single-fluid solver, the central-weighted-essentially-nonoscillatory(CWENO)-type central-upwind scheme, is developed from our previous works. The high resolution and the nonoscillatory quality of the scheme can be verified by solving several numerical experiments. Nonlinear sloshing inside a pitching partially filled rectangular tank with/without baffles has been investigated.

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The determination of real fluid requirements in laparoscopic resection of pheochromocytoma using minimally invasive hemodynamic monitoring: a prospectively designed trial

Surgical Endoscopy ◽

10.1007/s00464-019-06777-z ◽

2019 ◽

Vol 34 (1) ◽

pp. 368-376 ◽

Cited By ~ 3

Author(s):

Martin B. Niederle ◽

Edith Fleischmann ◽

Barbara Kabon ◽

Bruno Niederle

Keyword(s):

Minimally Invasive ◽

Hemodynamic Monitoring ◽

Laparoscopic Resection ◽

Real Fluid ◽

Invasive Hemodynamic Monitoring

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An experimental study of underexpanded sonic, coaxial, swirl jets

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/095440604322786974 ◽

2004 ◽

Vol 218 (1) ◽

pp. 93-103 ◽

Cited By ~ 4

Author(s):

K-H Lee ◽

T Setoguchi ◽

S Matsuo ◽

H-D Kim

Keyword(s):

Static Pressure ◽

Near Field ◽

Flow Structures ◽

Experimental Investigations ◽

Pressure Measurements ◽

Annular Nozzle ◽

Free Jets ◽

Underexpanded Jets ◽

Secondary Stream ◽

The Impact

The present study addresses experimental investigations of the near-field flow structures of an underexpanded sonic, dual, coaxial, swirl jet. The swirl stream is discharged from the secondary annular nozzle and the primary inner nozzle provides the underexpanded free jets. The interactions between the secondary swirl and primary underexpanded jets are quantified by a fine pitot impact and static pressure measurements and are visualized using a shadowgraph optical method. The pressure ratios of the secondary swirl and primary underexpanded jets are varied below 7.0. Experiments are conducted to investigate the effects of the secondary swirl stream on the primary underexpanded jets, compared with the secondary stream of no swirl. The results show that the presence of an annular swirl stream causes the Mach disc to move further downstream, with an increased diameter, and remarkably reduces the fluctuations of the impact pressures in the underexpanded sonic dual coaxial jet, compared with the case of the secondary annular stream with no swirl.

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