Opportunity at Air Force Research Laboratory (AFRL)
Novel Meshing Paradigms for Rocket Propulsion Flowfield Simulations
Aerospace Systems Directorate, RQ/Engineering, Applied Sciences/Computer Sci
||Edwards Air Force Base, CA 93524
This research focuses on the exploration of novel meshing paradigms for computational fluid dynamics simulations of internal rocket flowfields. Current meshing paradigms have both strengths and weaknesses. Cartesian meshes are efficient and accurate, but are not suitable for capturing near-wall boundary layer phenomena; curvilinear structured meshes are efficient, accurate, and suitable for boundary layers, but the grid generation is complex and tedious; unstructured meshes are much easier to generate and are well-suited to boundary layers, but they are relatively inefficient and are typically restricted to second-order accuracy at best. The technical approach is to combine different mesh types within a single flowfield simulation so that the domain is effectively mapped by the grid-types best suited to the local requirements. Thus, the off-body region can be represented by Cartesian meshes, while the near-body region is governed by body-fitted structured or unstructured meshes. Connectivity between the different mesh systems is usually accomplished using overset grid technology. We anticipate that the judicious combination of such mesh types can lead to over two orders of magnitude savings in computational time and provide significant enhancements of solution accuracy. The specific topic of interest is the development of such a multiple-mesh infrastructure for internal flowfields that are representative of rocket propulsion flowfields. Additional areas of interest include (1) automated adaptive mesh refinement technology, (2) effective domain decomposition and load balancing algorithms, and (3) improved overset interpolation and/or conservative flex-exchange methods for inter-mesh information transfer. Research and development will be conducted within an existing code infrastructure and the methods applied to rocket propulsion flowfields including solid motors, liquid engines, cryogenic turbomachinery and/or electric thrusters.
Computational fluid dynamics; Overset grids; Internal rocket flowfields; Adaptive mesh refinement;
Open to U.S. citizens
Open to Postdoctoral and Senior applicants