Development of Turbulence Models, Uncertainty Quantification and Optimization Tools for Aircraft and Turbomachinery Analysis and Design Washington University in St. Louis/NASA Glenn Research Center, Langley Research Center, Ames Research Center, Aeronautics Research Mission Directorate
One of the key goals of this research project has been to develop an improved turbulence model for RANS equations that can significantly increase the accuracy of flow simulations for separated flows, rough wall flows, flows with rotational and curvature effects, and flows with compressibility effects and temperature dependent eddy-viscosity. Development and implementation of rigorous and comprehensive uncertainty quantification (UQ) methodology was another main goal of this research project. The third objective of the project has been to conduct the aerodynamic shape optimization studies using both the deterministic adjoint approach and the stochastic surrogate approach. The research project directly addresses the critical areas listed under NASA’s Aeronautics Research Mission Directorate – Fundamental Aeronautics Program’s R&D priorities. In particular it addresses the NASA’s “CFD Vision 2030” goals. A strong interaction has been established with the researchers in the Computational Aerosciences branch of NASA Langley Research Center and with CFD researchers at Boeing-St. Louis and UTRC. This project is serving as an important catalyst in improving the research and higher education infrastructure in the state of MO. It is allowing major improvements in research infrastructure at Washington University in St. Louis (WU), Missouri University of Science and Technology (MS&T) and Lincoln University. The CFD simulation capability has significantly enhanced addressing research in important areas of Turbulence Modeling, Uncertainty Quantification and Aerodynamic Optimization. At Lincoln University (HBCU), the students are being trained in CFD technology for the first time in its history. The computing infrastructure has also enhanced with the installation of GPU computers at WU. As a result of these major improvements in research infrastructure, it has been possible to develop a new more accurate and very efficient turbulence model for RANS equations of fluid dynamics used in CFD simulations and development of a new methodology for uncertainty quantification and sensitivity analysis. New advanced CFD courses are being developed including the results of this research and students are being trained. Such a trained work force in advanced CFD is very much needed by the aerospace industry.
NASA EPSCoR Stimuli 2014 -15
This figure shows an example of three-dimensional subsonic flow in an S-duct widely used in an aircraft propulsion system. The flow is separated at the lower surface of the duct creating a separation bubble. It is very difficult to predict this flow field using CFD; one of the primary reason being the inability of existing turbulence models to accurately compute the flow using the RANS equations. The top figure shows the velocity contours depicting the separation bubble. The bottom figure shows the comparison of the measured pressure distribution and the computed pressure distribution for flow in the NASA Glenn S-duct using th newly developed Wray-Agarwal model as a result of this grant. Other industry standard turbulence models, namely the Sparlart-Allmaras and Shear-Stress-Transport k-w fail to give such a good comaprision.
Dr. Ramesh K. Agarwal, Science PI, Bayly Lab, Washington University in St. Louis
Dr. Mujeeb Malik, NASA Technical Monitor, Langley Research Center
Published on Dec 14, 2015
NASA Office of Education’s Aerospace Research & Career Development (ARCD) is pleased to release NASA EPSCoR Stimuli, a collection of univers...