CAREER: Aerodynamic modeling of energy harvesting in stratified boundary layers across scales

About This Grant

One of the most important applications of fluid dynamics is improving the design of turbomachinery. These devices exchange energy between a fluid and a rotor. They are used in many applications such as marine propulsion, aircraft, and ocean energy technologies. They generate complicated turbulent flows that are difficult to analyze. On top of that, turbulent flows in the atmosphere or ocean interact with the flow generated by the turbomachinery, which is often ignored in engineering analysis. This project will develop new computational tools to analyze turbomachinery flows in realistic operating environments. It will generate accurate models for modern turbines and uncover effects of environmental flows on turbine performance. Results will be checked against wind tunnel and field data. The models generated in the project will be open-source and shared with the public on GitHub. The project will also develop hands-on activities for K-12 students to learn about wind and power generation. The outcomes of the project will help improve U.S. energy infrastructure and encourage students to pursue careers in energy engineering. This project uses scale-resolving large eddy simulations to systematically unravel nonlinear interactions between stratified boundary layer flows, rotor aerodynamics, turbine wakes (momentum and turbulence), and array/boundary layer-scale entrainment and wakes. To guide design and control optimization with accurate predictions, this project develops open-source fast engineering models of these coupled, multi-scale dynamics. The models will be developed using targeted decompositions that first parse rotor aerodynamics from wakes, enabling thrust and power predictions using first principles, and then isolate turbulent wakes from the background stratified, turbulent boundary layer. This project will validate the models using large eddy simulations, wind tunnel experimental data, and field data. The first objective uses scale-resolving large eddy simulations to elucidate the coupled impacts of rotor operation and velocity shear on rotor thrust and power. This project then models synergistic rotor and boundary layer effects on turbulent wakes and the large-scale environmental response to arrays of energy harvesting devices, resulting in an engineering model that couples the predictions of turbine-scale wakes and array-scale entrainment and yields lower error than existing models that neglect or parameterize shear, stability, and turbulence. Finally, the model will be extended, and validated using large eddy simulations, to predict large-scale wakes of arrays. Together, this project produces cross-cutting impact for applications including stratified turbulence and high Reynolds number geophysical flows. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.