Iowa State University. Department of Aerospace EngineeringSukra Helitek Inc.Virginia Tech. Aerospace and Ocean Engineering DepartmentRajagopalan, R. GaneshGuntupalli, KanchanFischels, Mathew V.Novak, Luke A.2015-07-282015-07-282015-06Rajagopalan, R. G., Guntupalli, K., Fischels, M. V., & Novak, L. A. (2015, June). An analytical procedure for evaluating aerodynamics of wind turbines in yawed flow. Paper presented at the North American Wind Energy Academy 2015 Symposium, Blacksburg, VA.http://hdl.handle.net/10919/54691A new analytical method for evaluating the performance of wind turbines in yawed flow is presented. The method, based on momentum theory, relates the yaw angle to the tip-path-plane orientation of the turbine rotor and the non-dimensional deficit velocity. The analytical calculations are compared with results from Rot3DC, a kernel within the RotCFD software package, an integrated environment for rotors. Rot3DC, a 3-D Navier-Stokes based module, can simulate one or more Horizontal Axis Wind Turbines (HAWT) and uses the concept of momentum sources to compute the turbine performance and flowfield in a self contained manner. Rot3DC simulations are validated against NREL Phase-II experiments. Analytical results for yawed turbines correlate well with Rot3DC and are found to be within 10% error margin for the extreme yaws considered. The developed analytical formulation provides a simple model for quantification of turbine performance in yawed flow and can be used as an input to onboard feedback systems for yaw control.22 pagesapplication/vnd.ms-powerpointapplication/pdfen-USIn CopyrightPresentationRajagopalan, R. GaneshGuntupalli, KanchanFischels, Mathew V.Novak, Luke A.