A model for combustion instability involving vortex shedding

2003 ◽  
Vol 175 (6) ◽  
pp. 1059-1083 ◽  
Author(s):  
Konstantin I. Matveev ◽  
F. E. C. Culick
Keyword(s):  
Vortex Shedding ◽  
Combustion Instability

Revisiting a Model for Combustion Instability Involving Vortex Shedding

2009 ◽  
Vol 181 (3) ◽  
pp. 457-482 ◽  
Author(s):  
B. Tulsyan ◽  
K. Balasubramanian ◽  
R. I. Sujith
Keyword(s):  
Vortex Shedding ◽  
Combustion Instability

Vortex-driven acoustically coupled combustion instabilities

1987 ◽  
Vol 177 ◽  
pp. 265-292 ◽  
Author(s):  
Thierry J. Poinsot ◽  
Arnaud C. Trouve ◽  
Denis P. Veynante ◽  
Sebastien M. Candel ◽  
Emile J. Esposito
Keyword(s):  
Heat Release ◽  
Vortex Shedding ◽  
Combustion Instability ◽  
Low Frequency ◽  
Combustion Instabilities ◽  
Rayleigh Criterion ◽  
Phase Average ◽  
Steady Heat

Combustion instability is investigated in the case of a multiple inlet combustor with dump. It is shown that low-frequency instabilities are acoustically coupled and occur at the eigenfrequencies of the system. Using spark-schlieren and a special phase-average imaging of the C2-radical emission, the fluid-mechanical processes involved in a vortex-driven mode of instability are investigated. The phase-average images provide maps of the local non-steady heat release. From the data collected on the combustor the processes of vortex shedding, growth, interactions and burning are described. The phases between the pressure, velocity and heat-release fluctuations are determined. The implications of the global Rayleigh criterion are verified and a mechanism for low-frequency vortex-driven instabilities is proposed.

Combustion Instability Involving Vortex Shedding in Hybrid Rocket Motors

2013 ◽  
Author(s):  
Dario Pastrone ◽  
Lorenzo Casalino ◽  
Marco Codegone ◽  
Carlo Novara ◽  
Carmine Carmicino
Keyword(s):  
Vortex Shedding ◽  
Combustion Instability ◽  
Hybrid Rocket ◽  
Rocket Motors

Evolution of unstable system.

2015 ◽  
Vol 9 (3) ◽  
pp. 2487-2502 ◽  
Author(s):  
Igor V. Lebed
Keyword(s):  
Reynolds Number ◽  
Vortex Shedding ◽  
Stokes Flow ◽  
Stable Solution ◽  
The State ◽  
Unstable System ◽  
Unstable Flow ◽  
Unstable Solutions ◽  
Vortex Shedding Modes ◽  
Hydrodynamics Equations

Scenario of appearance and development of instability in problem of a flow around a solid sphere at rest is discussed. The scenario was created by solutions to the multimoment hydrodynamics equations, which were applied to investigate the unstable phenomena. These solutions allow interpreting Stokes flow, periodic pulsations of the recirculating zone in the wake behind the sphere, the phenomenon of vortex shedding observed experimentally. In accordance with the scenario, system loses its stability when entropy outflow through surface confining the system cannot be compensated by entropy produced within the system. The system does not find a new stable position after losing its stability, that is, the system remains further unstable. As Reynolds number grows, one unstable flow regime is replaced by another. The replacement is governed tendency of the system to discover fastest path to depart from the state of statistical equilibrium. This striving, however, does not lead the system to disintegration. Periodically, reverse solutions to the multimoment hydrodynamics equations change the nature of evolution and guide the unstable system in a highly unlikely direction. In case of unstable system, unlikely path meets the direction of approaching the state of statistical equilibrium. Such behavior of the system contradicts the scenario created by solutions to the classic hydrodynamics equations. Unstable solutions to the classic hydrodynamics equations are not fairly prolonged along time to interpret experiment. Stable solutions satisfactorily reproduce all observed stable medium states. As Reynolds number grows one stable solution is replaced by another. They are, however, incapable of reproducing any of unstable regimes recorded experimentally. In particular, stable solutions to the classic hydrodynamics equations cannot put anything in correspondence to any of observed vortex shedding modes. In accordance with our interpretation, the reason for this isthe classic hydrodynamics equations themselves.

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