Date of Award
Doctor of Philosophy
Aerospace Engineering; Wind Energy Science, Engineering, and Policy
R. G. Rajagopalan
The runtime of unsteady incompressible flows were reduced through different techniques in the formulation and solution of the governing equations. The implicit Runge-Kutta based IRK-SIMPLER algorithm was developed and compared to the Crank-Nicholson based SIMPLER and the explicit RK-SIMPLER algorithms. The IRK-SIMPLER algorithm was tested for steady and unsteady problems, both on structured Cartesian and unstructured vertex-centered median-dual grids, and proved to be an accurate and robust algorithm that also required less runtime. Further, a second order unstructured Flux Corrected Method improved the accuracy of flux calculation with minimal/negligible increase in runtime. The Flux Corrected Method provided a small stencil scheme that required little additional runtime compared to the commonly used Power Law scheme. Wind turbine cases were simulated with momentum source modeling. Both steady rotor models and three variations of the unsteady momentum source model were tested. The power predicted by the simulations matched experiments well, and for the cases presented, the simulations required 447 times less runtime than traditional methods.
Matthew Vincent Fischels
Fischels, Matthew Vincent, "Development of methods to improve the accuracy and efficiency of unsteady incompressible flow simulation" (2018). Graduate Theses and Dissertations. 16353.