Session: 09-09-01: Advances in Wind and Ocean Energy

Paper Number: 165972

Understanding the Effect of Scaling on Aerodynamic Force Analysis of NREL Phase VI Wind Turbine Blade 

Wind energy is one of the most versatile sources of renewable energy, which can greatly contribute to achieving environmental sustainability. Various design and analysis are considered on wind turbine as it is one of the major parts required to efficiently extract the wind energy.  Floating Offshore Wind Turbines (FOWTs) utilize wind and wave energy, which are an alternative to their land-based counterparts. Since FOWTs are not restricted by available land space, they can be made larger in size to increase the amount of power produced. For comprehensive study of FOWT, it is necessary to decrease their size, primarily for wind tunnel testing or to meet available computational demand of simulations. In order to predict how different sized rotor diameters will affect the performance of the turbines, two output parameters need to be considered; lift and drag. Since the main function of the turbine is to produce power, it is critical to know how much lift will be acting on the blade because this provides the torque. Drag is directly responsible for creating thrust, which causes bending stress on both the tower and blades as well as causing the platform to tilt in the surge direction. The goal of this work is to study aerodynamic forces such as lift and drag when the turbine blade is scaled to any size through numerical simulation. Computational Fluid Dynamics (CFD) is done using Ansys CFX software to simulate the pressure and velocity profiles over the NREL phase VI turbine blade. The results are obtained at 3 different incoming wind speeds: 5, 15, and 25 m/s, while the rotational speed is maintained at 72 rpm. From this simulation, the pressure, lift, and drag coefficients are calculated at different spans of the blade. Then the rotor diameter is scaled from its original diameter of 10.6 m up to 50 m and down to 5 m and tested at each of the three wind speeds. These diameters are chosen so the effects of scaling both up and down can be obtained. When scaling the blade there are many aspects of design to consider, such as the tip speed ratio, the twist of the blade, and the change in chord length, which can all be related directly to the rotor diameter. Results will be compared within different diameters of the blade to observe the effect of scaling on the prediction of aerodynamic loads. The integrated torque and thrust generated by the blade can be calculated from the results which can indicate the power output of any size of turbine. Measuring the thrust can be helpful in measuring the blade deformation through structural analysis. 

Presenting Author: Patrick R West Western Michigan University

Presenting Author Biography: Patrick R West is currently a master's student in mechanical and aerospace engineering at Western Michigan University. His research interest is in renewable energy focusing on experimental and computational analysis of wind turbines and turbine blade designs.

Authors:

Patrick R West Western Michigan University
Shrabanti Roy Western Michigan University
Xiaoyun Shao Western Michigan University