Performance of Solid Propellant Rocket Motors with Variation in Nozzle Geometry

The nozzle geometry affects the performance achieved by a solid propellant rocket motor to a great extent. In order to improve the development of a small home made solid propellant rocket motor these effects on performance from the nozzle geometry need to be understood. This thesis project involves the design of a small solid propellant rocket motor with materials readily available to a hobby rocket enthusiast. A specific investigation is then carried out into the effects that nozzle geometry has on the thrust and impulse performance of the rocket motor. The thrust-time profiles of the rocket motors are achieved by conducting a static firing in a cantilever beam thrust measuring apparatus. A secondary study is also done on these different nozzle geometries using computation fluid dynamics simulations to determine the predicted thrust performance. This also gives the advantage of visualizing the entire flow field and assists in identifying the features that drive the differences in performance. Overall this project develops a high performance nozzle geometry for use on a small home made solid propellant rocket motor as well as outlining various engineering issues involved with the development of a solid propellant rocket motor.