Design and Geometrical Analysis of Propellant Grain Configurations of a Solid Rocket Motor

Design and analysis of propellant grain configurations for determination of the grain geometry which is an important and critical step in the design of solid propellant rocket motors, because accurate calculation of grain geometrical properties plays a vital role in performance prediction. The performance prediction of the solid rocket motor can be achieved easily if the burn back steps of the grain are known. In this study, grain burn back analysis for 3-D star grain geometries for solid rocket motor was investigated. The design process involves parametric modeling of the geometry in CATIA software through dynamic variables that define the complex configuration. Initial geometry is defined in the form of a surface which defines the grain configuration. Grain burn back is achieved by making new surfaces at each web increment and calculating geometrical properties at each step. Equilibrium pressure method is used to calculate the internal ballistics. The procedure adopted can be applied to any complex geometry in a relatively simple way for preliminary designing of grain configuration. As the propellant in the igniter burns which would reduce the area of the remaining propellant and by which there will be an change of pressure in the Solid Rocket Motor with respect to the time and this change in the pressure with cause variation in mass flow rate and in this paper the variation of the thrust with respect to the time is calculated .The areas of the grain are found by using MATLAB using 0.05 mm half set and which is gives the area of the remaining grain in the Solid Rocket Motor. The numerical results from the CATIA are checked with the MATLAB and to verify the correct area of the remaining propellant.