Projects

Active Projects

Indiana Wind

Within the scope of the research project Indiana Wind, time-resolved CFD simulations of the flow around a wind turbine are performed, taking into account the fluid-structure interaction and controller at complex flow conditions. The results will be used to investigate the formation of acoustic sound waves in the low-frequency range. The influence of vortex generators (VG) on aeroacoustics is evaluated with respect to their direct sound emission as well as their influence on the trailing edge emission of the rotor due to the modifications of the boundary layer characteristics. Furthermore, the project investigates the noise sources for thick flatback airfoils and attempts to reduce this noise source by employing flow control mechanisms. The noise is evaluated using time-resolved CFD-CAA approaches with the help of the Ffowcs Williams Hawkings method. The pressure fluctuations obtained from the CFD solutions will be feed into the acoustic solver developed at the institute.

In the project I contribute on the execution and evaluations of the high fidelity computations of wind turbines equipped with controllers under the influences of complex flow conditions and aeroelastic effects. I also perform the aerodynamic and aeroacoustic simulations of the flatback airfoils and determine the possible countermeasures for reducing the emitted noise disturbances.

Funded by the Federal Ministry of Economics and Technology of Germany

Wind Turbine Aerodynamics – Modeling using CFD approaches

This project is funded by the American Institute of Physics Publishing (AIPP). I am contracted by the AIPP to write a teaching book entitled “Wind Turbine Aerodynamics Modeling using CFD approaches”. The book is expected to be finished by 2022 and should be published early 2023. My role is the the author of the book and as the principal investigator (PI) for the funding application.

Funded by the American Institute of Physics Publishing

B-GO

Accurate predictions of wind turbine performance are important aspects for modern rotor design, but also challenging tasks due to complex physical phenomena. High fidelity computational fluid dynamics (CFD) approaches are obviously out of the game because the calculations have to be carried out very efficiently within the design phase. Unfortunately, the well known blade element momentum (BEM) methods are not accurate enough when the induction effect is high.The main aim of the project is for developing a dedicated simplified tool for wind turbine calculations.

We initiated this project at IAG from early 2018 up to present. Within the project, a robust, accurate but easy-to-learn momentum code is continuously developed. The name of the code B-GO is derived from an Indonesian word “Bego” that literally means “stupid”. Philosophically the code is made for everybody to be able to learn programming and it is very easy to use – even by the stupid person. Currently the code supports simplified calculations for HAWT and VAWT. For possible collaboration, please send an email to bangga@iag.uni-stuttgart.de

B-GO results for HAWT B-GO results for VAWT

Past Projects

Curriculumsentwicklung im Rahmen der Stuttgarter Lehr/Lernlabore für das Wintersemester 2019/2020

Aerodynamics and acoustics are two subjects of interest for the success of wind turbine project development. Both aspects affect not only the turbine performance but could influence the community acceptance towards the erection of wind turbines on some specific sites. Within this project, we aim at developing a new course at the University of Stuttgart to introduce these aspects to the students. The goal is to enable the students to perform first evaluations of wind turbine aerodynamics and how this will influence the noise generation of the turbine.

Within this project, we acquired a funding for developing a new course “Wind Energy Aerodynamics and Acoustics” at the University of Stuttgart. My role were as a principal investigator (PI) together with the leader of our research group and as the lecturer of the course.

Funded by the Ministry for Science, Research and Art of Baden-Wuerttemberg

Mexnext – IEA Task 29

The main focus of the Mexnext project is detailed aerodynamic assessment of wind turbines. The studies include comparisons of high fidelity CFD models, free wake and BEM with dedicated experimental campaigns. In Phase I the attention of the project was intensified on the measurements which have been carried out within the Mexico project funded by the European Union. Phase II investigated a wide variety of field and wind tunnel measurements. Special focus was given for yawed flow, unsteady aerodynamics, 3D effects, tip effects, near wake aerodynamics, standstill, etc. and it included a preparatory phase of the New Mexico experiment presented in Phase III. While the past 3 phases were devoted for the wind tunnel measurements, Phase IV (2018-2020) is focused on the field measurement of a commercial scale wind turbine. The project involves participation of universities, research institutions and industries from 3 different continents.

We contribute to the full scale aerodynamic and aeroelastic calculations of the investigated turbine in Phase IV by means of CFD simulations employing three-dimensional URANS and eddy-resolving DES approaches. Furthermore we coordinate the workpackage WP3.1 (Phase IV) dedicated for the aerodynamic response to turbulent inflow.

DSWind

he main focus of this project is the improvement of dynamic stall models for wind turbine applications. The studies are carried out from October 2018. The project is divided into three main tasks: (1) experimental campaign of airfoils under the influence of dynamic stall, (2) high fidelity URANS and (D)DES simulations of airfoils under the influence of dynamic stall, and (3) dynamic stall modelling based on information gained from the experimental and simulation campaigns. We contribute to the high fidelity URANS simulations of airfoils under the influence of dynamic stall and the improvement of dynamic stall models. Particular interests are given in the stall regime not only for positive but also for negative angles of attack.

Funded by Wobben Research and Development, Germany

WINSENT

Within the project, two research wind turbines will be installed in the mountainous complex terrain of the Swabian Alb. The turbines will have a hub height of approx. 75 m and a rotor diameter of approx. 50 m. The wind fields in the terrain will be characterized by measuring masts equipped with various sensors for speed measurement. In addition, a model chain will be developed within the framework of the project in order to carry out realistic CFD simulations.

Contribution: Within the project I provided support by generating the aerodynamic polar data using URANS simulations for the purpose of engineering simulations.

Winsent Page

AVATAR

AVATAR is a project initiated by the European Energy Research Alliance (EERA), carried out under the FP7 program of the European Union. The motivation for the AVATAR project lies in the fact that up-scaling wind turbines towards 10-20 MW is expected to lead to radical innovations and design challenges in order to make such turbines feasible and cost effective. Many of these innovations (i.e. design philosophies leading to slender blades with tailored aeroelastic characteristics, thick airfoils, high tip speeds and the use of distributed flow control devices) have a strong aerodynamic component and can be considered as unconventional from an aero-elastic point of view: they violate assumptions in current tools on e.g. compressibility and Reynolds number effects, as well as assumptions on flow transition and separation effects, all in combination with a much more complex flow-structure interaction. Hence the analysis of these up-scaled rotor designs falls outside the validated range of applicability of the current state of the art computational aeroelastic tools. AVATAR will therefore bring the aerodynamic and aeroelastic models to a next level and calibrate them for all relevant aspects which are expected to play a role at large (10MW+) wind turbines.

Contribution: I contribute to detailed assessments into the flow physics and mechanisms of the three-dimensional effects occurring in the root area of the AVATAR blade. The centrifugal and Coriolis forces are responsible for the enhanced lift component. The inviscid effect also present but not as strong as in the generic rotor blade. Drag force is mainly reduced by the 3D effects, but locally increases due to standing vortices in the root area.

EERA Homepage | AVATAR Homepage