Written by Peter Drown Thursday, 01 April 2010 00:00
Part 1: Modeling
Engineers see the world differently than everybody else. Where we see a pile of sawdust, AEWC engineers see the building material for a structure that can withstand hurricanes. In response to decaying infrastructure, researchers at AEWC developed a bridge that can be set up in under a week, and eliminates the need for large crews and heavy equipment. AEWC engineers are constantly pushing the limit of what can be done to solve important problems.
Now, they are tackling another complex assignment: building a floating structure that will enable massive wind turbines to float in the stormy Gulf of Maine. The idea has tremendous potential—turbines, out of sight and out of mind, taking advantage of the steady ocean winds, and cleanly and reliably providing electricity for millions of people. I visited two engineers working on this project to discover how they planned to take on this enormous challenge.
"You have to be an expert on everything," explained Andrew Goupee, a Ph.D. in Mechanical Engineering, who brings valuable expertise in numerical modeling to the project. Before a wind turbine is put out on the water, researchers need to study the conditions of the wind and waves in the area, so they can adjust the turbine to be able to withstand those conditions. They develop models to help them with this task, "codes" they can use to test the prototypes. Currently, the DeepCWind Consortium has a buoy deployed at the University of Maine Deepwater Offshore Wind Test Site just south of Monhegan Island that records important data such as wave heights and wind speed.
Besides being a great Scrabble word, this form of testing is important when solving the greatest challenges in developing platforms for offshore wind turbines to cope with the hostile environment of the ocean.
Hydrodynamic refers to the pressure placed on floating turbines from the waves and forces under the surface of the ocean. Aeroelastic refers to pressure from the wind and forces above the surface. Data is available for aeroelastic properties of onshore turbines, and hydrodynamic properties of offshore oil platforms, but learning about the pressures faced by floating, offshore wind turbine is uncharted territory. Understanding these forces is crucial for researchers and engineers to develop a turbine that will withstand the harsh wind and waves in the Gulf of Maine.