BALLISTIC SIMULATION, ANALYSIS AND DESIGN OF A SINE-STAR GRAIN CONFIGURATION

摘要

In the design of a solid-propellant rocket motor, a predetermined thrust law (thrust-time relationship) is generally one of the main design considerations. Thus, the main task of the designer is to choose the suitable grain configuration and solid-propellant type (double base, composite, etc.) which satisfy the required thrust law. Therefore, the geometric analysis of the selected configuration has a crucial importance in the grain design process. In this work, a new grain configuration, sine-star, for solid-propellant rocket motors is suggested. The suggested grain configuration consists of a sine wave imposed on a base circle. Formulation and modeling of the internal ballistic parameters of the considered sine-star configuration are carried out according to the burning rate law of the solid propellant. New simulation algorithm was also designed to obtain the accurate shape of the propellant burning area of the sine-star grain configuration during the burning process. This algorithm is not only restricted to sine-star grain configuration but also can be applied to the other side burning grain configurations. Ballistic analysis and optimization of the design parameters for the considered sine-star grain configuration are conducted to compare the suggested grain configuration with the traditional star grain configuration. To carry out the mentioned above tasks a ballistic computer aided design approach is used. This approach leads to design of a Sine-Star computer package. The output of the package can be obtained as ASCII file, DXF file, or in the form of graphical relationships. To check the accuracy and reliability of output results of the Sine-Star computer package, some methods have been carried out to verify the results obtained by this package. The sine-star grain configuration not only has the same advantages of the star grain configuration but also reduces the number of independent variables that define the star grain configuration and, in turn, facilitates the analysis and optimization of the configuration.