Simulation of Spatially Developing Plane and Round Jets

1998 ◽  
pp. 301-318 ◽  
Author(s):  
P. Comte ◽  
Y. Dubief ◽  
C. Brun ◽  
M. Meinke ◽  
C. Schulz ◽  
...  
Keyword(s):  
Round Jets

scholarly journals Parameter governing the far-field features of round jets

2016 ◽  
Vol 1 (6) ◽  
Author(s):  
Xi Xia ◽  
Kamran Mohseni
Keyword(s):  
Far Field ◽  
Round Jets

Behavior of Unsteady Turbulent Starting Round Jets

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Neerav Abani ◽  
Jaal B. Ghandhi
Keyword(s):  
High Speed ◽  
Penetration Rate ◽  
Injection Rate ◽  
Injection Velocity ◽  
Time Varying ◽  
Velocity Change ◽  
Rate Of Penetration ◽  
Round Jets ◽  
The Difference ◽  
Sudden Decrease

Turbulent starting jets with time-varying injection velocities were investigated using high-speed schlieren imaging. Two solenoid-controlled injectors fed a common plenum upstream of an orifice; using different upstream pressures and actuation times, injection-rate profiles with a step increase or decrease in injection velocity were tested. The behavior of the jet was found to be different depending on the direction of the injection-velocity change. A step increase in injection velocity resulted in an increased rate of penetration relative to the steady-injection case, and a larger increase in injection velocity resulted in an earlier change in the tip-penetration rate. The step-increase data were found to be collapsed by scaling the time by a convective time scale based on the tip location at the time of the injection-velocity change and the difference in the injection velocities. A sudden decrease in injection velocity to zero was found to cause a deviation from the corresponding steady-pressure case at a time that was independent of the initial jet velocity, i.e., it was independent of the magnitude of the injection-velocity change. Two models for unsteady injection from the literature were tested and some deficiencies in the models were identified.

The transient start of supersonic jets

2007 ◽  
Vol 578 ◽  
pp. 331-369 ◽  
Author(s):  
MATEI I. RADULESCU ◽  
CHUNG K. LAW
Keyword(s):  
Numerical Simulations ◽  
Ambient Air ◽  
Hydrogen Gas ◽  
Shock Interactions ◽  
Round Jets ◽  
Reactive Gases ◽  
Acoustic Instabilities ◽  
Diffusive Fluxes ◽  
Experimental Findings ◽  
Good Agreement

This study investigates the initial transient hydrodynamic evolution of highly under-expanded slit and round jets. A closed-form analytic similarity solution is derived for the temporal evolution of temperature, pressure and density at the jet head for vanishing diffusive fluxes, generalizing a previous model of Chekmarev using Chernyi's boundary-layer method for hypersonic flows. Two-dimensional numerical simulations were also performed to investigate the flow field during the initial stages over distances of ~ 1000 orifice radii. The parameters used in the simulations correspond to the release of pressurized hydrogen gas into ambient air, with pressure ratios varying between approximately 100 and 1000. The simulations confirm the similarity laws derived theoretically and indicate that the head of the jet is laminar at early stages, while complex acoustic instabilities are established at the sides of the jet, involving shock interactions within the vortex rings, in good agreement with previous experimental findings. Very good agreement is found between the present model, the numerical simulations and previous experimental results obtained for both slit and round jets during the transient establishment of the jet. Criteria for Rayleigh–Taylor instability of the decelerating density gradients at the jet head are also derived, as well as the formulation of a model addressing the ignition of unsteady expanding diffusive layers formed during the sudden release of reactive gases.

Active open-loop control of particle dispersion in round jets

AIAA Journal ◽  
1994 ◽  
Vol 32 (3) ◽  
pp. 555-563 ◽  
Author(s):  
Ellen K. Longmire ◽  
John K. Eaton
Keyword(s):  
Particle Dispersion ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Round Jets

A Numerical Study on Pores per Inch Effect on Impinging Round Jets in Channel Partially Filled With Metal Foam

2021 ◽  
Author(s):  
Bernardo Buonomo ◽  
Furio Cascetta ◽  
Anna Di Pasqua ◽  
Oronzio Manca ◽  
Sergio Nappo
Keyword(s):  
Metal Foam ◽  
Numerical Study ◽  
Round Jets
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