DOI: https://doi.org/10.15368/theses.2022.23
Available at: https://digitalcommons.calpoly.edu/theses/2450
Date of Award
2-2022
Degree Name
MS in Engineering
Department/Program
Mechanical Engineering
College
College of Engineering
Advisor
Patrick Lemieux
Advisor Department
Mechanical Engineering
Advisor College
College of Engineering
Abstract
This thesis report outlines the creation of a MATLAB tool to design reversible machines that can function as both wind turbines and as agricultural frost protection fans. Frost protection fans are used to prevent crop loss during radiative freeze events during which a temperature inversion is present. Such a dual-purpose machine fundamentally has the constraint that it must use symmetric airfoils, so a suite of tools for automatically designing an optimized wind turbine blade with symmetric airfoils using the Blade Element Momentum (BEM) theory approach is presented. The BEM code is then re-derived and adapted for use with a frost protection fan, which is analogous to a propeller at zero free-stream windspeed. The relative performance of a blade operating in fan mode is investigated using a turbulent jet entrainment model to predict the time-averaged temperature rise provided by the fan during a thermal inversion event. With these tools, an optimal configuration of blade pitch angle, rotor tilt angle, and tower height can be found for a given wind turbine blade. The models are incorporated into a cohesive program with a graphical user interface. The feasibility of such machines is found to depend heavily on the wind resource at a given site.