Flow Fields of Interacting Parallel Supersonic Free Jets.

Niimi, Tomohide; Fujimoto, Tetsuo; Taoi, Nobumasa

doi:10.1299/jsmeb.39.95

Cited by 6 publications

(5 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is clear that the shock structure predicted using the larger and smaller computational domains is quite consistent with each other. Such complicated shock structure has been observed earlier [6] for highly underexpanded (P e /P amb ≈ 100) twin round jets also. In the present case of twin plane jet flow, the UE ratio (UE = P e /P amb ) is approximately equal to 2.85.…”

Section: Effect Of Grid Sensitivity and Domain Sizesupporting

confidence: 74%

“…For high-speed twin jets, the variations in Mach number and nozzle spacing have significant effects on the shock cell pattern as well as on the mixing process. With the help of flow visualization experiments, the complicated shock structure associated with highly underexpanded twin jets has been studied [6]. Experimental investigations on twin non-parallel high-speed jets [7] demonstrate the influence of nozzle spacing and angle of interception on jet merging and evolution.…”

Section: Introductionmentioning

confidence: 99%

“…The engine performance could be severely compromised if the sand from the fountain flow is ingested by the engine. In such multiple high-speed jets, the presence of a neighbouring jet influences the near-field shock structures, entrainment of ambient fluid, and the rate of spread [6,22,23]. In solid rocket motors, the combustion exhaust contains hot propellant particles (Al 2 O 3 and Al), which are sometimes entrained in the recirculatory flow between the jets, thereby causing erosion of the nozzle base [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Interaction between particle-laden underexpanded twin supersonic jets

Varun

Sundararajan

Usha

et al. 2010

Proceedings of the Institution of Mechanical Engineers, Part G:

View full text Add to dashboard Cite

This paper presents numerical results on the near-field interactions of particle-laden twin supersonic jets operating in underexpanded mode, with special emphasis on the effects of particles on jet flow expansion. Although plane jets have been considered primarily, a few cases of twin round jets have also been simulated for the sake of comparison. Three turbulence models (Spalart—Allmaras, k—ɛ (realizable), and k—ω (sst)) have been considered for incorporating turbulent interaction effects in two-phase supersonic jets. In general, the k—ω (sst) model gives better predictions in the reverse flow as well as in the shock regions. The recirculatory flow is enhanced at high underexpansion (UE) ratios, and the size and strength of the recirculation region are much smaller for twin round jets than those for plane jets. In particle-laden jets, small particles (corresponding to Stokes number less than 0.05) are entrained in the recirculation zone, whereas particles of larger size are not trapped. With large particles, a particle-free zone occurs close to the nozzle wall in the divergent section. Small particles follow the gas phase with negligible non-equilibrium effects, but they also cause higher two-phase drag, resulting in a higher degree of jet UE.

show abstract

Section: Effect Of Grid Sensitivity and Domain Sizesupporting

confidence: 74%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Interaction between particle-laden underexpanded twin supersonic jets

Varun

Sundararajan

Usha

et al. 2010

Proceedings of the Institution of Mechanical Engineers, Part G:

View full text Add to dashboard Cite

show abstract

“…The flow fields of two, three or four interacting parallel supersonic free jets are also studied by flow visualization using planar LIF of I 2 molecules seeded in argon [8]. Centers of orifices are set linearly and on vertices of a triangle or square.…”

Section: Visualization Of Flow Field Structures Using Lifmentioning

confidence: 99%

Optical Diagnostics of Nonequilibrium Phenomena in Highly Rarefied Gas Flows

Niimi¹

2003

AIP Conference Proceedings

Self Cite

View full text Add to dashboard Cite

The necessity of non-intrusive measurement of the thermodynamic variables in rarefied gas flows has motivated the development of optical diagnostics, such as electron beam fluorescence, laser induced fluorescence, coherent anti-Stokes Raman scattering, and so on. These spectroscopic methods have enabled to detect the nonequilibrium in the gas flows, based on the internal energy distributions obtained from spectral profiles. In this paper, the laser-based techniques for detection of the nonequilibrium phenomena in the highly rarefied gas flows and some results obtained by us are described.

show abstract

“…Thus, only a few of experimental studies are available. 19,20 Therefore, numerical analysis becomes a very attractive option. For the flow in the rarefied regime, the DSMC method has proven to be a powerful technique and many researchers 21,22 have used the method for the dual interacting jets expanding into vacuum, such as Zhu and Dagum, 5-7 Ketsdever, 9 and Wu.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Interacting, Under-Expanded, Rarefied Jets

Li¹,

Ladeinde²

2010

46th AIAA/ASME/SAE/ASEE Joint Propulsion Conference &Amp;amp; Exhibit

View full text Add to dashboard Cite

A numerical study, using the Direct Simulation Monte Carlo (DSMC) approach, of the interaction effects between two identical sonic under-expanded nitrogen jets under rarefied conditions is reported. In this paper, the effects of the jet stagnation Knudsen number (Kn s), the ratio of the stagnation-to-background pressure (P s /P b), and the distance between the jet orifices (L/D) were investigated for a range of these parameters. The background pressure has a very significant effect on the physics of flow. The value of L/D affects the locations of the Mach disk in both primary and secondary jets. But When P s /P b is relatively large (such as P s /P b =220) and L/D is relatively small (L/D≤6.0), the separation distance L/D has only a mild effect on the location of the Mach disk in the secondary jet. A study of the rotationaltranslational non-equilibrium showed that large deviations between the translational and rotational temperatures can be found in the secondary jet, especially in the vicinity of the orifice plate.

show abstract

Flow Fields of Interacting Parallel Supersonic Free Jets.

Cited by 6 publications

References 2 publications

Interaction between particle-laden underexpanded twin supersonic jets

Interaction between particle-laden underexpanded twin supersonic jets

Optical Diagnostics of Nonequilibrium Phenomena in Highly Rarefied Gas Flows

Analysis of Interacting, Under-Expanded, Rarefied Jets

Contact Info

Product

Resources

About