Optimization of secondary-air addition in a continuous one-dimensional spray combustor

A framework is established for optimal control of continuous combustors using the sequential linear quadratic algorithm. An analysis is presented for liquid-fuel vaporization and burning in a continuous combustor with secondary-air addition at downstream locations. A steady one-dimensional flow is portrayed and a system of nonlinear ordinary differential equations is established. Three combustion models are presented with different rate-controlling processes: vaporization, vaporization-mixing, and vaporization-mixing-reaction. The models have a sufficient number of characteristic times and sufficient nonlinearity to provide a challenge to an optimization procedure. The proposed method yields an optimal distribution of secondary-air addition.