Study on Nonlinear Dynamics Using the State Space of Combustion Oscillation in a Rocket Combustor

Combustion oscillation in a rocket combustor was analyzed using Variational Auto-Encoder (VAE). Dimension reductions were conducted on various physical quantities (p′, ˙q′, etc.) the combustor. Orthogonal modes obtained proper orthogonal decomposition for output of VAE. Pumping and damping regions identified distribution Rayleigh Index each mode. Three characteristic that supply energy to oscillation. A phase plane spanned by latent variables reductions. Activation six mapped plane. The three found be activated at different phases. From trajectory plane, confirmed satisfy requirements state space. In high-pressure amplitude phase, pumping near wall clarified.