Automatic control of propellant combustion stability in a semiclosed space

The possibility of changing the boundary of stable combustion of propellants in a semiclosed space is examined within the framework of the linear automatic control theory. Analysis is performed using the Zel’dovich-Novozhilov theory in conjunction with the isothermal approximation for the combustion products. Characteristic equations for determining the stability boundary were derived for various control laws: proportional, proportional-differential, and proportional-integral ones. It was demonstrated that, depending on the values of the governing parameters (propellant properties, apparatus constant) and control law form, the stability boundary could expand or contract.