Modelling of Solid Rocket Motors (SRMs) with a Coupled-Level-Set-and-Volume-Of-Fluid (CLSVOF)-Approach

The development of 3D additive manufacturing of energetic materials promises the ability to produce solid rocket motors (SRMs) with a tailored thrust curve. This can be achieved by using multiple fuel layers with different combustion properties or a complex fuel grain geometry. To avoid the time and cost consuming development of processing and experimental investigations with the task of designing the SRM, a numeric model is needed for complex, heterogenous SRMs. The numeric model needs to describe two parts: First the surface regression of the fuel grain caused by the combustion and second the fluid dynamics of the gas inside the combustion chamber and the rocket nozzle. The Level-Set-Method (LSM) is used for the surface regression model and the Volume-Of-Fluid (VOF)-Approach is used to merge the surface regression model with a CFD-solver. The result is the Coupled-Level-Set-and-Volume-Of-Fluid (CLSVOF)-Approach. An experiment in a standard combustion chamber was simulated. The results were compared with experimental data to validate the model.