Surface regression model for heterogenous solid rocket motors

New manufacturing methods such as 3D-printing enable the design of Solid Rocket Motors (SRMs) with thrust curves tailored to mission requirements. This can be achieved using complex shapes for the burning surface and arranging different solid fuels with different combustion properties and burning rates. It is desirable to simulate the behavior of the SRM as it is more cost efficient and faster than experimental testing of the SRM, especially because 3D-printing is a slow process. The Level-Set-Method (LSM) was chosen to simulate the surface regression of SRMs. The LSM has already been used to simulate surface regression of the burning surface of homogenous SRMs. However, these models cannot be used to describe the surface regression for multiple different solid fuels burning at the same time. To accurately model the surface regression of heterogenous SRMs, the LSM based model is connected to a multidimensional model describing the combustion chamber. This is necessary to account for local pressure differences and erosive burning both of which affect the surface regression rate. The new models combine a surface regression model with a CFD-model to describe the burning of heterogenous SRMs with the intention to test and optimize possible SRM geometries.