SIMULATION OF INTERNAL BALLISTIC SOLID ROCKET MOTOR

Abstract

Solid Rocket Motors (SRM) manufacturing and design were expensive. In the design to develop the solid propellant rocket motors, the use of numerical tools able to simulate, predict and reconstruct the behavior of a given motor in all operative conditions is particularly important in order to decrease the planning and costs to avoid made destructive test. The study is devoted to present an approach to the numerical simulation of a given Solid Propellant Rocket Motor (SPRM) internal ballistics, 122 mm, during the quasi steady state by means of a commercial tool (ANSYS FLUENT). The main goal of the work is to study and simulate charged motor for long range (20~40km) rocket (122mm) motor internal ballistics (thrust & pressure). The internal ballistics model constructed in the study is a 2-D axisymmetric model, based on several assumptions that there is no contribution of the erosive burning and dynamic burning in the burning rate model. The results of the internal ballistics simulation are compared with that obtained from the experimental ground firing test station for three models with original. The validation of the results allows concluding that the assumptions made in the construction of the model are reasonable. Good agreement observed between theoretical, analytical and experimental results. In the study some of the conventional 2-D grain burn backs are analyzed and thrust - pressure time histories are predicted by plotting some graphs in different temperature ranges (20, 35, 50) ºC. These graphs are validated by comparing the ground static firing test data obtained by Ballistic Test Motor. ANSYS FLUENT simulation can improve to investigating other solid rocket motors which used in missile or rockets or any other type of ammunitions which is high cost to investigate with experimental ground firing test station. The study allow make use of computers to model the test of SRM that eliminate cost of SRM research.