At NASA, there is an increased interest in using Computational Fluid Dynamics (CFD) tools to evaluate different aircraft designs and analyze their performance. The commonly used hybrid approaches employing Reynolds Averaged Navier Stokes (RANS) in attached regions and Large Eddy Simulation (LES) in regions of flow unsteadiness and separation, suffers from many issues related to the generation of resolved turbulence at the RANS/LES interface degrading their predictive accuracy. CRAFT Tech proposes to develop an integrated, modular, well-validated software toolset for the generation of acoustically adapted synthetic turbulence to be used in conjunction with any zonal hybrid RANS/LES approaches. This software toolset is envisioned to be a collection of STG approaches that are suited for various CFD codes used by NASA. Due to the artificial nature of the generated turbulence, it may not be entirely possible to avoid propagation of artificial acoustic disturbances from the interface. To address this, the toolset would also include an optional acoustic module than can be used to filter out spurious pressure fluctuations arising from the RANS/LES interface due to the synthetic turbulence generation. Many of the required feature sets for development and testing of the proposed toolset such as hybrid RANS/LES and WMLES turbulence models are already present in CRAFT CFD® and CRUNCH CFD® multi-physics codes developed and maintained at CRAFT Tech. The modeling capability will provide NASA with the means to efficiently characterize the flow across a RANS/LES interface thus drastically improving the predictive capability of the hybrid method. The toolset will be capable of interfacing with major CFD codes used by NASA such as FUN3D, LAVA, and OpenNCC, among others.
Using the SBIR modeling tools, NASA would be uniquely well-positioned to explore the design of innovative next-generation aircraft and hypersonic transport components. The models developed in Phase I and II would be invaluable in demonstrating the advantages of Hybrid RANS/LES with STG over the currently adopted industry-standard RANS approaches, with emphasis on the minimization of technical risk due to the use of its demonstrated high-fidelity predictive capability.
The modeling tools will be commercially licensed to prime vendors and supporting organizations engaged in the development of aircraft components. CRAFT Tech presently licenses CFD software to the aerospace industry under varied licensing terms and these active commercial relationships will be significantly enhanced by the software toolset that will be developed under the proposed SBIR program.