Publications

Zinser, Brian; Blake, Samuel B.; Pfeiffer, Robert A.; Huang, Andy H.; Himbele, John J.; Freno, Brian A.; Dang, Vinh Q.; Kotulski, J.D.; Rajamanickam, Sivasankaran R.; Johnson, William Arthur.; Campione, Salvatore; Langston, William L.

Abstract not provided.

Journal of Computational Physics

Freno, Brian A.; Carnes, Brian C.; Weirs, Vincent G.

The study of hypersonic flows and their underlying aerothermochemical reactions is particularly important in the design and analysis of vehicles exiting and reentering Earth's atmosphere. Computational physics codes can be employed to simulate these phenomena; however, verification of these codes is necessary to certify their credibility. To date, few approaches have been presented for verifying codes that simulate hypersonic flows, especially flows reacting in thermochemical nonequilibrium. In this paper, we present our code-verification techniques for verifying the spatial accuracy and thermochemical source term in hypersonic reacting flows in thermochemical nonequilibrium. We demonstrate the effectiveness of these techniques on the Sandia Parallel Aerodynamics and Reentry Code (SPARC).

Freno, Brian A.; Carnes, Brian C.; Weirs, Vincent G.

Abstract not provided.

Zinser, Brian; Blake, Samuel A.; Pfeiffer, Robert A.; Huang, Andy H.; Himbele, John J.; Freno, Brian A.; Dang, Vinh Q.; Kotulski, J.D.; Rajamanickam, Sivasankaran R.; Johnson, William Arthur.; Campione, Salvatore; Langston, William L.

Abstract not provided.

Freno, Brian A.; Carnes, Brian C.; Weirs, Vincent G.

Abstract not provided.

AIAA Scitech Forum

Ray, Jaideep R.; Kieweg, Sarah K.; Dinzl, Derek J.; Carnes, Brian C.; Weirs, Vincent G.; Freno, Brian A.; Howard, Micah A.; Smith, Thomas M.

We propose herein a probabilistic framework for assessing the consistency of an experimental dataset, i.e., whether the stated experimental conditions are consistent with the measurements provided. In case the dataset is inconsistent, our framework allows one to hypothesize and test sources of inconsistencies. This is crucial in model validation efforts. The framework relies on Bayesian inference to estimate experimental settings deemed uncertain, from measurements deemed accurate. The quality of the inferred variables is gauged by its ability to reproduce held-out experimental measurements. We test the correctness of the framework on three double-cone experiments conducted in the CUBRC Inc.'s LENS-I shock tunnel, which have also been numerically simulated successfully. Thereafter, we use the framework to investigate two double-cone experiments (executed in the LENS-XX shock tunnel) which have encountered difficulties when used in model validation exercises. We detect an inconsistency with one of the LENS-XX experiments. In addition, we hypothesize two causes for our inability to simulate LEXS-XX experiments accurately and test them using our framework. We find that there is no single cause that explains all the discrepancies between model predictions and experimental data, but different causes explain different discrepancies, to larger or smaller extent. We end by proposing that uncertainty quantification methods be used more widely to understand experiments and characterize facilities, and we cite three different methods to do so, the third of which we present in this paper.

AIAA Aviation 2019 Forum

Freno, Brian A.; Carnes, Brian C.; Weirs, Vincent G.

The study of hypersonic flows and their underlying aerothermochemical reactions is particularly important in the design and analysis of vehicles exiting and reentering Earth’s atmosphere. Computational physics codes can be employed to simulate these phenomena; however, code verification of these codes is necessary to certify their credibility. To date, few approaches have been presented for verifying codes that simulate hypersonic flows, especially flows reacting in thermochemical nonequilibrium. In this paper, we present our code-verification techniques for hypersonic reacting flows in thermochemical nonequilibrium, as well as their deployment in the Sandia Parallel Aerodynamics and Reentry Code (SPARC).

Kieweg, Sarah K.; Ray, Jaideep R.; Weirs, V.G.; Carnes, Brian C.; Dinzl, Derek J.; Freno, Brian A.; Howard, Micah A.; Phipps, Eric T.; Rider, William J.; Smith, Thomas M.

Abstract not provided.

Kieweg, Sarah K.; Ray, Jaideep R.; Weirs, Vincent G.; Carnes, Brian C.; Dinzl, Derek J.; Freno, Brian A.; Howard, Micah A.; Phipps, Eric T.; Rider, William J.; Smith, Thomas M.; Nompelis, Ioannis N.; Candler, Graham C.

Abstract not provided.

Ray, Jaideep R.; Kieweg, Sarah K.; Dinzl, Derek J.; Carnes, Brian C.; Weirs, Vincent G.; Freno, Brian A.; Howard, Micah A.; Smith, Thomas M.; Nompelis, I.N.; Candler, G.V.C.

Abstract not provided.

Ray, Jaideep R.; Kieweg, Sarah K.; Dinzl, Derek J.; Carnes, Brian C.; Weirs, Vincent G.; Freno, Brian A.; Howard, Micah A.; Smith, Thomas M.; Nompelis, Ioannis N.; Candler, G.VC.

Abstract not provided.

Carnes, Brian C.; Arienti, Marco A.; Mussoni, Erin E.; Freno, Brian A.; Weirs, Vincent G.; Smith, Thomas M.; Rider, William J.

Abstract not provided.

Carnes, Brian C.; Arienti, Marco A.; Freno, Brian A.; Mussoni, Erin E.; Weirs, Vincent G.; Smith, Thomas M.

Abstract not provided.

Crozier, Paul C.; Howard, Micah A.; Rider, William J.; Freno, Brian A.; Bova, S.W.; Carnes, Brian C.

The SPARC (Sandia Parallel Aerodynamics and Reentry Code) will provide nuclear weapon qualification evidence for the random vibration and thermal environments created by re-entry of a warhead into the earth’s atmosphere. SPARC incorporates the innovative approaches of ATDM projects on several fronts including: effective harnessing of heterogeneous compute nodes using Kokkos, exascale-ready parallel scalability through asynchronous multi-tasking, uncertainty quantification through Sacado integration, implementation of state-of-the-art reentry physics and multiscale models, use of advanced verification and validation methods, and enabling of improved workflows for users. SPARC is being developed primarily for the Department of Energy nuclear weapon program, with additional development and use of the code is being supported by the Department of Defense for conventional weapons programs.