Simulation of a rocket motor involves many disciplines, including three broad physical disciplines--fluid dynamics, solid mechanics, and combustion--that interact with each other at the primary system level, with additional subsystem level interactions, such as particles and turbulence within fluids. Because of its complex and cross-disciplinary nature, the development of Rocstar has been intrinsically demanding, requiring diverse backgrounds within the research team. In addition, the capabilities required from the individual physical disciplines are at the frontier of their respective research agendas, which entails rapid and independent evolution of their software implementations.
To accommodate the diverse and dynamically changing needs of individual physics disciplines, we have adopted a partitioned approach, to enable coupling of individual software components that solve problems in their own physical and geometrical domains. With this approach, the physical components of the system are naturally mapped onto various software components (or modules), which can then be developed and parallelized independently. These modules are then integrated into a coherent system through an integration framework, which, among other responsibilities, manages the distributed data objects, and performs inter-module communications on parallel machines.