Hopf Bifurcation Analysis of the Combustion Instability in a Liquid Rocket Engine

The bifurcation process of self-sustained combustion instability pressure perturbations in a liquid rocket combustor is investigated based on the Helmholtz equations and dependent flame describing function. modal frequency growth rates are numerically resolved by commercial software COMSOL multiphysics. Validation numerical approach firstly conducted Rijke tube combustor, supercritical for first longitudinal mode observed. diagrams transverse different time delays gain index function analyzed. Only presents this configuration. trajectory Hopf points diagram feature period motions with increasing delay. effect length distributions analyzed considering non-uniform distribution model. Results show that has large impact process, e.g., more unstable distribution. Finally, subcritical found when complicated considered; bistable region condition discussed.