The Relationship of the Nozzle Exit Gas Velocity with the Combustion Chamber Pressure of Solid Propellant Engines

Abstract

This research included an analytical study of the nozzle theory for solid propellant rockets, And the basic concepts on which the nozzle theory depends. This research studied and concluded the relationship between the exit gases velocity and the pressure of combustion chamber in the solid propellant rockets, which is one of the most useful relationships, in addition to the relationship of the cross-sectional ratio (the nozzle exit area to the nozzle throat area), which determines the optimum expansion ratio for the nozzle.

The research also included some calculations related to the study and design of the nozzle, where the velocity of gas flow at the nozzle exit was calculated as a function of the combustion chamber pressure, drawing the relationship curve between them, calculating the optimum expansion ratio for the nozzle and the diameter of the nozzle exit, for one of the types of propellant, which is potassium nitrate-sorbitol (KNSB).