Effect of Downstream Microjet Fluidic Injection on Mixing Characteristics of Supersonic Jet

Numerical and Experimental Studies on the Supersonic Coaxial Jet Mixing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.354-355.691 ◽

2011 ◽

Vol 354-355 ◽

pp. 691-695

Author(s):

N. Karthikeyan ◽

B T N Sridhar

Keyword(s):

High Speed ◽

Cfd Simulation ◽

Experimental Studies ◽

Supersonic Jet ◽

Vortex Structures ◽

Engineering Systems ◽

Experimental Conditions ◽

Jet Mixing ◽

Pressure Profiles ◽

Mixing Characteristics

Coaxial nozzles are an integral part of many engineering systems where mixing of different fluid streams is required. Single noncircular nozzles have been shown to have better mixing characteristics than their axisymmetric counterparts. Therefore, a combination of such nozzles into coaxial configurations is promising. The aim of the present study is to quantitatively determine the effects of the geometry of the primary supersonic jet on the mixing characteristics with the secondary high speed subsonic jet. Measurements of pressure profiles at several positions along central axis of jets using identical facilities and nominally identical experimental conditions were done. The mixing is dominated by the vortex structures that are present in the inner shear layers. The interaction of the vortex structures govern the growth, and entrainment, and mixing of the jet. Also, the experimental results show that the radial and centerline pressure profiles through various coaxial jets has good correlation with the CFD simulation.

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Mixing Characteristics of Supersonic Jet from Bevelled Nozzles

International Journal of Heat and Technology ◽

10.18280/ijht.390226 ◽

2021 ◽

Vol 39 (2) ◽

pp. 559-572

Author(s):

Bholu Kumar ◽

Suresh Kant Verma ◽

Shantanu Srivastava

Keyword(s):

Nozzle Exit ◽

Supersonic Jet ◽

Area Ratio ◽

Mixing Enhancement ◽

Ansys Fluent ◽

Jet Mixing ◽

Circular Nozzle ◽

Mixing Characteristics ◽

Commercial Software Package ◽

Axis Switching

The present study focuses on the effect of nozzle exit inclination on the mixing characteristics of Mach 2.17 overexpanded jets at the NPR 5, NPR 6 and NPR 7, using commercial software package ANSYS Fluent. The convergent-divergent nozzles, investigated are circular nozzle and bevel nozzle with bevel angle 300, and bevel angel 450. The nozzles are constructed with equal throat-to-exit area ratio, in order to maintain uniform Mach number at the nozzle exit. From the results, it was found that, the bevelled nozzles effectively reduce the jet core as much as 46%, indicating enhanced jet mixing. It was also observed that at lower NPR, i.e., at NPR 5, the Bevel30 nozzle is found superior over Bevel45 and circular nozzle and at the intermediate NPR, both of the Bevel30 and Bevel45 nozzle reduces the jet core with the same rate. However, at highest NPR of the present study, the Bevel45 nozzle exhibits the highest mixing enhancement. An early axis switching is seen for the Bevel30 jet at NPR 5 and for the Bevel45 jet at NPR 7.

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