Flow Stucture of Supersonic Underexpanded Jet With Microjets Injection

2013 ◽  
Vol 8 (1) ◽  
pp. 44-55
Author(s):  
Dmitriy Gubanov ◽  
Valeriy Zapryagaev ◽  
Nikolay Kiselev
Keyword(s):  
Flow Structure ◽  
Numerical Study ◽  
Mixing Layer ◽  
Supersonic Jet ◽  
Wave Structure ◽  
Streamwise Vortices ◽  
Jet Mixing ◽  
Underexpanded Jet ◽  
Supersonic Underexpanded Jet ◽  
The Impact

Experimental and numerical study of transversal microjets injection influence on the supersonic underexpanded jet flow structure has been performed. Data of measurements and calculation have acceptable agreement. Interaction of microjets with main supersonic jet sets to a decrease of an initial gasdynamic region. Microjets lead to a longitudinal streamwise vortices generation and a mushroom-like flow structures create on an external jet mixing layer. Dissipation of longitudinal streamwise vortices was observed at the second jet cell. Complex gasdynamic flow structure of the supersonic underexpanded jet interacting with supersonic microjets has been studied for the first time. This structure contains system of complex chock waves and expansion waves spreading from the position of the impact microjets/main jet localization place. Future of interaction process a chock-wave structure of main jet with additional shock waves has been studied

On the Impingement of Supersonic Jet on a Normal Flat Surface

1982 ◽  
Vol 33 (3) ◽  
pp. 199-218 ◽  
Author(s):  
B.N. Pamadi
Keyword(s):  
Flat Surface ◽  
Supersonic Jet ◽  
Improved Method ◽  
Normal Surface ◽  
Underexpanded Jet ◽  
Flow Parameters ◽  
Supersonic Underexpanded Jet ◽  
Method Of Integral Relations ◽  
Integral Relations ◽  
Good Agreement

SummaryAn improved method, based on one strip approximation of the method of integral relations which was reported originally by Belov, Ginzburg and Shub, is presented for the calculation of flow parameters in the impingement region of a supersonic, underexpanded jet striking a normal surface located within the first cell. The results are presented for two impingement conditions and found to be in good agreement with the experimental data.

Mach waves produced in the supersonic jet mixing layer by shock/vortex interaction

Shock Waves ◽  
2016 ◽  
Vol 26 (3) ◽  
pp. 231-240 ◽  
Author(s):  
H. Oertel Sen ◽  
F. Seiler ◽  
J. Srulijes ◽  
R. Hruschka
Keyword(s):  
Mixing Layer ◽  
Supersonic Jet ◽  
Vortex Interaction ◽  
Jet Mixing ◽  
Mach Waves

Study of Decay Characteristics of Hexagonal and Square Supersonic Jet

2017 ◽  
Vol 34 (2) ◽  
Author(s):  
Prasanta Kumar Mohanta ◽  
B. T. N. Sridhar
Keyword(s):  
Pressure Ratio ◽  
Supersonic Jet ◽  
Ambient Air ◽  
Hydraulic Diameter ◽  
Schlieren Image ◽  
Image Study ◽  
Jet Mixing ◽  
Core Length ◽  
Supersonic Core Length ◽  
The Impact

AbstractExperiments were carried on nozzles with different exit geometry to study their impact on supersonic core length. Circular, hexagonal, and square exit geometries were considered for the study. Numerical simulations and schlieren image study were performed. The supersonic core decay was found to be of different length for different exit geometries, though the throat to exit area ratio was kept constant. The impact of nozzle exit geometry is to enhance the mixing of primary flow with ambient air, without requiring tab, wire or secondary method to increase the mixing characteristics. The non-circular mixing is faster comparative to circular geometry, which leads to reduction in supersonic core length. The results depict that shorter the hydraulic diameter, the jet mixing is faster. To avoid the losses in divergent section, the cross section of throat was maintained at same geometry as the exit geometry. Investigation shows that the supersonic core region is dependent on the hydraulic diameter and the diagonal. In addition, it has been observed that number of shock cells remain the same irrespective of exit geometry shape for the given nozzle pressure ratio.

scholarly journals Experimental study of a supersonic jet-mixing layer interaction

2004 ◽  
Vol 16 (3) ◽  
pp. 765-778 ◽  
Author(s):  
E. Collin ◽  
S. Barre ◽  
J. P. Bonnet
Keyword(s):  
Experimental Study ◽  
Mixing Layer ◽  
Supersonic Jet ◽  
Jet Mixing ◽  
Layer Interaction

scholarly journals Influence of input methods on jet mixing in a four-vortex chamber

2021 ◽  
Vol 2088 (1) ◽  
pp. 012010
Author(s):  
A A Dekterev ◽  
V A Kuznetsov ◽  
E S Tepfer
Keyword(s):  
Flow Structure ◽  
Turbulence Model ◽  
Vortex Structure ◽  
Numerical Study ◽  
Vortex Chamber ◽  
Vortex Structures ◽  
Jet Mixing ◽  
Calculation Results ◽  
Sst Turbulence Model

Abstract In this work, a numerical study of aerodynamics and interaction of vortex structures is carried out depending on the organization of the injection of jets in the chamber. For unsteady calculation of aerodynamics, the URANS approach based on the k-omega SST turbulence model was used. The calculation results show the conditions for the formation of a stable four-vortex structure. The options are also identified in which a significant restructuring of the flow structure occurs.

Investigation on the Source Locations of Axisymmetric Screech Tones Utilizing Data from Numerical Simulation

2019 ◽  
Vol 27 (04) ◽  
pp. 1850058
Author(s):  
Incheol Lee ◽  
Duck Joo Lee
Keyword(s):  
Mach Number ◽  
Fourth Order ◽  
Mixing Layer ◽  
Supersonic Jet ◽  
Shock Cell ◽  
Jet Mixing ◽  
Screech Tone ◽  
Runge Kutta Method ◽  
Cell Structures ◽  
Screech Tones

The source locations of axisymmetric modes of screech tones are numerically investigated. Fourth-order optimized compact scheme and fourth-order Runge–Kutta method are used to solve the 2-D axisymmetric Euler equations. The screech tone is successfully reproduced, and the change in wavelength with respect to jet Mach number shows good agreement with the experimental data. At various low supersonic jet Mach numbers, the time-averaged contours of Mach number and root-mean-square pressure are investigated to identify the location of maximum interaction between shock cell structures and vortices. The source locations of two axisymmetric modes, A1 and A2 modes, are distinctly visualized and identified; the screech tones of A1 mode are generated at the apex of fifth shock cell, and the screech tones of A2 mode are generated at the apex of fourth shock cell. Based on the observation, a simple formula for the prediction of axisymmetric modes of screech tones is proposed. The formula is derived based on a form of Rossiter equation, with the assumption of different convection speeds along the jet mixing layer. The proposed formula successfully estimates the frequency of two axisymmetric modes of screech tones, which verifies that the identified source locations of the axisymmetric screech tones are reasonable.

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