No abstract

Despite that many sophisticated prediction tools are made to explicate the phenomena of internal ballistic for dual thrust rocket motor due to geometry change, none of them discussed uncertainties due to geometric, ballistic and regression simultaneously. Mathematical models are developed on the basic governing theories to estimate the pressure time history for two tubular grains with two different diameters along the grain. A Computer module was made to facilitate this study with consideration to uncertainties as they have a noticed effect on the results. The need for an optimization tool was necessary to reduce the error between theoretical and experimental results, genetic algorithm (MATLAB toolbox) was used as optimization tool. A set of static firing test are made for validation and to determine the operating characteristics of the motors experimentally. It was apparent in this study that some of these uncertainties are applicable in large scale motors only and the others are applicable for both small, and large scale motors.

No abstract

The Dual-Thrust Rocket Motors (DTRMs) are the most widely used solid propulsion system for anti-tank guided missiles. DTRM with intermediate nozzle is a special type of this system. Depending on the internal conditions, the flow through the intermediate nozzle can be sonic, subsonic or reversed. The objective of this paper is to understand the internal ballistics (IB) and phenomena of DTRM with sonic intermediate nozzle. In this study, a mathematical model describing the performance of this DTRM is derived from the main governing equations of internal ballistics. Also, a set of experiments is conducted using a developed test motor to inspect the physics of DTRM with sonic intermediate nozzle and assess the mathematical model validity. Results of the mathematical model have shown a good agreement compared with those from the experimental studies.

Boost-sustain solid propellant rocket motors have been used to meet the demand for short and medium range tactical missiles. These motors obtain a wide variety of thrust-time profiles if the propellant characteristics and grain geometry are properly selected. These Dual Thrust Rocket Motors (DTRM) can have various designs; the DTRM with an intermediate nozzle is one design that yields a high boost-sustain thrust ratio with a stable operation. Under certain conditions, the flow through the intermediate nozzle at the start of motor operation can be reversed.The present paper is intended to understand the phenomena and determine the operating parameters of DTRM with the reverse flow intermediate nozzle. In this study, a mathematical model describing the performance is derived from the main governing equations of internal ballistics (IB). Also, a set of experiments are conducted so as to inspect the details of the physics of such configuration DTRM. The experimental findings are utilized to validate the mathematical model.Results of the theoretical and experimental investigation explain most of the IB characteristics that were not discussed before in the open literature.