Direct prediction of unstable waves in combustion chamber

Aiming at a direct, also more realistic, prediction of unstable waves evolving in the combustion chamber, present paper introduces a new analytical method. Instability equations are freshly formulated, and solve the time-integrated ODE's for amplification factors to find the transients of pressure and velocity fluctuations. Present numerical approach requires no separate treatments for nonlinearities. Preliminary numerical experiments for unstable waves in quasi-onedimensional rocket combustor, show validity and applicability of present model, and promise for its practical use. Study for the complex models for physics, especially velocity- and pressure-coupled responses, and inclusion of multi dimensionality remains as future tasks.