Advanced study of aerodynamics, fluid-structure interaction and design optimization of wind turbines (MDO-WT)

Faculty Development Competitive Research Grants 2020-2022

Computational study of unsteady aerodynamics and fluid-structure interaction on wind turbine blades and rotors is to be conducted. These interactions are of direct relevance to the design of wind turbines that are to be used for more efficient power generation. The proposed program is designed to provide a new and more accurate approach for wind turbine analysis and design compared with existing ones, and results will be validated by experimental measurements available in the open literature. We propose a new approach of aerodynamic analysis: whole field analysis by using high performance computing (HPC) technologies in hardware and numerical methods. Specifically we propose to use a rotating block grid on a rotating coordinate system for computing the flow around the whole wind turbine rotor based on the URANS (Unsteady Reynolds-averaged Naviers-Stokes) and hybrid URANS+LES (Large Eddie Simulation) i.e., HURANSLES models and use a stationary block grid on a stationary coordinate system for the wake flow field and combine the two flow fields by a sliding grid approach. By the new whole field analysis approach, we will be able to overcome all the shortcomings of the current engineering analysis of wind turbines and have a better understanding of the true flow physics. The computational results will then be validated by published experimental measurements. The whole field results are then used to calibrate the simulation of fluid-structure interaction on individual blades as well as rotors. Finally a fast physics-based goal driven multi-disciplinary design optimization (MDO) method combining aerodynamic design optimization (ADO) and structural design optimization (SDO) will be devised and integrated with the CFD+FSI (Fluid Computational Fluid Dynamics and Structure Interaction) solvers. In summary, we aim to achieve the following objectives in this project:

1) To develop a new whole-field approach for the aerodynamic analysis of wind turbines using the state-of-the –art computational technologies.
2) To develop/adopt advanced 4DCFD solvers based on Multi-block Grid (MBG), URANS and HURANSLES models for fluid-structure interaction (FSI) for single blades and whole rotors (4DCFD+FSI).
3) To develop fast and effective physics-based goal driven multi-disciplinary design optimization (MDO) methods for the aerodynamic and structural dynamic design optimization (ADO+SDO) of wind turbine blades and rotors (4DCFD+FSI+MDO).
4) To perform MDO to maximize power output and minimize material use for blades and rotors while maintaining their structural integrity using the developed system.

Scientific novelty and significance
The following key points highlight the novelty of the project:
1) Multi-block grid (MBG) 4DCFD approach with rotating and stationary meshes, URANS, HURANLES for whole rotor aerodynamic simulation: this approach is rarely attempted by researchers worldwide
2) The above advanced 4DCFD approach with Fluid Structure Interaction (FSI) using Arbitrary-Lagrangian Eulerian (ALE) method inside the rotating mesh round the rotor for fluid and structure interaction through our dynamic mesh approach [38], advanced URANS and HURANSLES models (simply called 4DCFD+FSI) on HPC platforms: completely new attempt
3) 4DCFD are integrated with 3D modeller and physics-based aerodynamic design optimizer (ADO) for rigid blades and rotors (4DCFD+ADO): we have currently trying this, new attempt [39]
4) 4DCFD+FSI are integrated with 3D modeller and physics-based aerodynamic design optimizer (ADO) for rigid blades and rotors (4DCFD+FSI+ADO): completely new attempt ]
5) 4DCFD+FSI+ADO are coupled with Structural Design Optimizer (SDO) to perform multi-disciplinary design optimization for maximum power output with minimum material use while maintaining structural integrity (4DCFD+FSI+MDO): completely new attempt
This project will generate new knowledge and develop cutting edge technologies which will provide greater insight into the highly complex flow physics around wind turbines and change the way engineers design the next generation of wind turbines.