ForWind (Center for wind energy research)
Design of mini wind turbine for rotor power experiments
Wind energy has become one of the most important sources of generating electricity. Not like other energy generating processes like coal, gas and oil which is hazardous to the atmosphere, it is a clean form of energy, which doesn’t pollute the environment. In the 21st century, the cost of generating electricity from the wind has become cheaper therefore making it affordable for many communities to use.
A modern wind turbine consists of 2 or 3 bladed rotors which are made of fiberglass, which is mounted at the top of a tower (usually made of concrete, steel and or wood). Energy is converted from the mechanical energy of the wind into electrical energy with the use of a generator.
There are many reasons why there are usually three blades. The most important reason which is based on physics is aerodynamic efficiency. As the number of blades increases, the aerodynamic efficiency also increases. As a result of diminishing returns having more than three blades leads to minimal improvements in aerodynamic efficiency.
Task of the experiment
The Power Coefficient CP tells how efficiently a turbine converts the energy in the wind to electricity. Once the blade has been designed for optimum operation at a specific design tip speed ratio (which is defined as the ratio between the blade tip speed and the wind speed), the performance of the rotor over all expected tip speed ratios needs to be determined. For each tip speed ratio, the aerodynamic conditions at each blade section need to be determined. From these, the performance of the total rotor can be determined. The results are usually presented as a graph of power coefficient (CP) versus the tip speed ratio (λ). This graph is called the CP-λ curve.
After solving for the tip speed ratio (λ) in all the blade sections, we will then calculate for the blade twist and chord length, which will be used for rapid prototyping of the rotor blade in Autodesk Inventor. The rotor blade experiment will be carried out in a small wind tunnel with wind speed of 10m/s, by means of a small Wind Turbine.
A Fly Wheel (a rotating mechanical device that is used to store rotational energy) will be attached to the back of the small wind turbine, which will be used to measure the power produced by the rotor at different tip speed ratios.
The second project focuses on cost structures and related consequences for building a wind farm, including the lifetime of the turbines and operation and maintenance costs. We get to learn how to utilize wind energy by selecting and placing wind turbines using a simulator software called WindPro for a given wind farm border in Oldenburg, Germany. We have used our knowledge of wind energy utilization to formulate a wind farm layout that ensures maximum yield at minimum costs, abiding the rules and regulations set by both science and society.
The project discussed about the site location and layouts, the choice of wind turbines, the yields, the economics and environmental aspects of building a wind farm.