Description: The current state of the art for production computational fluid dynamic (CFD) simulations in both the Entry, Descent and Landing (EDL) communities and modeling of hypersonic vehicles is the solution of steady-state problems on fixed computation grids. However, the majority of relevant challenge problems are unsteady. Accurate simulations of such unsteady phenomena currently require computational grids that are overly refined, i.e., in large portions of the domain or even globally. An effective method to alleviate over-refinement, and associated cost, is the application of automatic mesh adaptation. Mesh adaptation applies refinement in the vicinity of critical flow features while coarsens at other areas and can significantly reduce the time-to-solution in terms of both overall computation time and hands-on gridding. However, a production-level unsteady mesh adaptation capability for aerothermodynamic analysis involving high-speed viscous flows (with boundary layers and strong unsteady shocks) is yet to be developed. In the proposed effort, Corvid Technologies, LLC (Corvid) and Rensselaer Polytechnic Institute (RPI) will develop an unsteady/time-accurate adaptive simulation capability for hypersonic flows with evolving geometries. Corvid and RPI will leverage couple high-fidelity components for CFD simulation of hypersonic vehicles, error indication/estimation and feature detection for mesh adaptation triggers, and geometry and mesh modification to provide the adaptive workflow.

Benefits: The proposed solution would directly benefit NASA’s EDL programs by delivering a robust, unsteady CFD modeling capability with decreased computational cost and decreased time to solution without degradation of solution accuracy for reentry modeling. Programs include Orion, Mars sample return, Mars 2020, deployable heatshield programs (HIAD, ADEPT), and planetary missions. This capability would also accelerate and improve the fidelity of modeling spacecraft being developed by NASA commercial partners such as SpaceX, Boeing, and Sierra Nevada.

Applications in the Army, Navy, Air Force and Missile Defense Agency, as well as in programs led by large defense prime contractors such as Raytheon, Lockheed Martin, Boeing, and Northrop Grumman, could use the CFD capabilities developed in this work. The component-based workflow in the proposed effort is highly adaptable to existing tools utilized within the CFD industry.