Project Title: Sensitivity of 3D Rocket Computational Fluid Dynamics (CFD) Simulation Results to Modeling Choices Adviser: Dr. Mark D. Brandyberry (CSAR) Project Description The Center for Simulation of Advanced Rockets has spent over ten years developing the Rocstar computational system to model the internal ballistics (core flow) of solid propellant rockets. Rocstar has multiple CFD packages, Solid Mechanics modules, and propellant burn-rate models, as well as multiphysics modules such as burning particles and smoke, and several turbulence modules. To model a specific rocket problem, it is not always obvious which CFD or structural package to use, which turbulence model to use, or whether to model particles or not. In fact, in some instances, different results may be obtained by using different combinations of models. It will be the objective of this work to set up a series of 2D and 3D computational models for one or more rocket problems, and to compare and contrast the results obtained for each model with nominally identical runs performed with different sets of models. The goal of this work will be to explore the potential ranges of results that can be obtained for a nominally identical problem due to the choice of different CFD packages, computational grids, turbulence models, etc. These insights will be used to consider what kind of modeling uncertainties should be assigned to rocket simulations using these models. Student Background and expected research activities We are looking for a student with strong interest in fluid mechanics, as well as an interest in highperformance computing and computational modeling. It would be helpful if the student was familiar with CAD tools (for building grid models). Being comfortable working in Linux would also be helpful, since the Rocstar code only runs on UNIX/Linux type systems. The majority of the project will require running different simulations of one or more solid propellant rockets and post-processing and comparing the results obtained. Due to the sensitive nature of the rocket data that will be used in this project, only U.S. citizens or permanent residents can be considered. Point of Contact Dr. Mark D. Brandyberry: mdbrandy@illinois.edu Funding: DOE-CSAR
Gas Velocity Contours Showing Vortex Shedding in a Solid Rocket Motor Simulation Core Flow