A Computational Study of Transverse Combustion Instability Mechanisms

Abstract

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Modeling of a coaxial liquid oxygen/gaseous hydrogen injection element under high-frequency acoustic disturbances

“…Modeling of rocket engine injectors under transverse acoustic excitation has been conducted by various other research groups using largeeddy simulation (LES) [22,23] and URANS [24]. Flattening, §apping, and retraction of the liquid oxidizer core from a coaxial injection element under transverse acoustic excitation have previously been identi¦ed in methane §ames using LES [22].…”

Large Eddy Simulations of Transverse Combustion Instability in a Multi-element Injector

“…This is unlike previous work by Shipley et al which failed to produce limit cycle amplitude in an unstable configuration. 19 The center of the chamber is a pressure node for the 1W mode and a pressure anti-node for the 2W mode, Figure 5 shows the unsteady pressure at the center of the chamber. Here again the simulations predict similar amplitudes for each of the two configurations.…”

“…Frame 9, the high pressure point, shows a significant rate of fuel consumption for both injectors. Prior studies by Shipley et al 19 stated the importance of vortex impingement of the driving injector with each other as an amplification method. That phenomenon is not present in this case, possibly because the lower amplitude transverse wave does not bring the two vortices sufficiently close to each other.…”

“…There was a long transient behavior which showed periods of instability growth and instability damping. 19 The current C 2 H 6 /RP1 setup was also modeled using a reduced approach where the solution was solved on multiple coupled grids by Popov and Sirignano. In their approach one-dimensional grids are used inside the injector ports, two-dimensional axisymmetric grids are used to model the combustion region in the chamber and a two-dimensional planar grid is used for the acoustics in the combustor.…”