Reduction in Line Deviation by Re-design of Propulsion System of a Multi Nozzle Rocket System: A Case Study

Abstract

This paper presents the study undertaken to determine the effect of ballistic parameters on line deviation of an unguided rocket. A detailed external ballistic study of a multiple canted nozzle rocket system was carried out and a code developed using a six degree of freedom (6 DOF) trajectory model. Aerodynamic coefficients determined from CFD studies were used for estimation of line deviation. Results of actual trials were used to validate the code. A study of effect of various parameters such as thrust misalignment, wind, variation in inertial properties, mass imbalance, initial velocity and spin on the rocket performance were carried out from simulation studies. Based on the analysis and study, various methods were employed to successfully eliminate the line deviation. Subsequently, design modifications were incorporated and dynamic trial with modified design were carried out successfully with reduction in line deviation.