Computational Fluid Dynamic (CFD) simulation are critical to the advancement of current and future flight vehicle designs, especially in the earlier design stages. Ground tests, such as wind tunnel testing, are unable to capture all of the flight envelope and conditions but can be used for flowfield discovery and verification & validation. The cost of building a prototype vehicle and flight tests is prohibitive, all but eliminating flight tests as a development tool. Computational fluid dynamics, if executed with thorough validation and verification efforts, can fill the gap left by physical testing. This research opportunity will pursue high fidelity modeling and simulation approaches to improve the implementation of CFD as design simulation of flight vehicles. This could include model testing and improvement, applying high-fidelity simulation approaches to cover areas of the flight envelope inaccessible with ground testing, working with experimentalists to validate simulation models and methods, and addressing the applicability and usefulness of the methods that have been developed.