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207 results on '"Bangga, Galih"'

54. Editorial: Climate change challenge-a wind energy perspective.

Author

Bangga, Galih

Subjects
GREY Wolf Optimizer algorithm, RENEWABLE energy sources, SUSTAINABLE development, EARTH (Planet), SUSTAINABILITY
Abstract

This article is an editorial that discusses the importance of wind energy in addressing climate change. It highlights the depletion of fossil fuels, the fear of an energy crisis, price volatility, and people's desire for cleaner energy sources as drivers for the rapid development and demand in wind energy. The editorial also mentions a research topic collection on wind energy and its role in tackling climate change. It briefly summarizes some key research outcomes, including the use of prediction tools for wind turbine performance evaluation and the optimization of wind farms. The article concludes by emphasizing the increasing role of statistical approaches in wind energy assessment and predictions, as well as the potential integration of digital twin technologies in wind energy systems. [Extracted from the article]

Published
2024
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57. Accuracy of the gamma re-theta transition model for simulating the DU-91-W2-250 airfoil at high reynolds numbers

Author

Michna, Jan, Rogowski, Krzysztof, Bangga, Galih, Hansen, Martin O.L., Michna, Jan, Rogowski, Krzysztof, Bangga, Galih, and Hansen, Martin O.L.

Abstract

Accurate computation of the performance of a horizontal-axis wind turbine (HAWT) using Blade Element Momentum (BEM) based codes requires good quality aerodynamic characteristics of airfoils. This paper shows a numerical investigation of transitional flow over the DU 91-W2-250 airfoil with chord-based Reynolds number ranging from 3 × 106 to 6 × 106. The primary goal of the present paper is to validate the unsteady Reynolds averaged Navier-Stokes (URANS) approach together with the four-equation transition SST turbulence model with experimental data from a wind tunnel. The main computational fluid dynamics (CFD) code used in this work was ANSYS Fluent. For comparison, two more CFD codes with the Transition SST model were used: FLOWer and STAR-CCM +. The obtained airfoil characteristics were also compared with the results of fully turbulent models published in other works. The XFOIL approach was also used in this work for comparison. The aerodynamic force coefficients obtained with the Transition SST model implemented in different CFD codes do not differ significantly from each other despite the different mesh distributions used. The drag coefficients obtained with fully turbulent models are too high. With the lowest Reynolds numbers analyzed in this work, the error in estimating the location of the transition was significant. This error decreases as the Reynolds number increases. The applicability of the uncalibrated transition SST approach for a two-dimensional thick airfoil is up to the critical angle of attack.

Published
2021

61. Three-dimensional flow in the root region of wind turbine rotors

Author

Bangga, Galih and Krämer, Ewald (Prof. Dr.-Ing.)

Abstract

This book presents the state of the art in the analyses of three-dimensional flow over rotating wind turbine blades. Systematic studies for wind turbine rotors with different sizes were carried out numerically employing three different simulation approaches, namely the Euler, URANS and DDES methods. The main mechanisms of the lift augmentation in the blade inboard region are described in detail. The physical relations between the inviscid and viscous effects are presented and evaluated, emphasizing the influence of the flow curvature on the resulting pressure distributions. Detailed studies concerning the lift augmentation for large wind turbine rotors are considered as thick inboard airfoils characterized by massive separation are desired to stronger contribute to power production. Special attention is given to the analyses of wind turbine loads and flow field that can be helpful for the interpretation of the occurring physical phenomena. The book is aimed at students, researchers, engineers and physicists dealing with wind engineering problems, but also for a wider audience involved in flow computations.

Published
2020
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62. Investigations of HAWT Airfoil Shape Characteristics and 3D Rotational Augmentation Sensitivity Toward the Aerodynamic Performance Improvement

Author

Kim, Youjin, Bangga, Galih, and Delgado, Antonio

Subjects
lcsh:GE1-350, lcsh:TD194-195, lcsh:Environmental effects of industries and plants, lcsh:TJ807-830, rotational augmentation, lcsh:Renewable energy sources, boundary layer, airfoil, HAWT, ddc:600, aerodynamics, lcsh:Environmental sciences
Abstract

This study investigates the impacts of dierent airfoil shapes on the 3D augmentationand power production of horizontal axis wind turbines (HAWTs). The aerodynamic eect fromchanging the leading and trailing edge of the airfoil is the emphasis of the research. Varied powerproduced from modifying sensitivity on 3D augmentations, caused by revamping airfoil shapes, areshown. The 3D correction law, considering the chord to radius ratio and the blades&rsquo, pitch angle inthe rotation, is applied to the airfoil lift coecients. The blade element method (BEM) embeddedin the software Qblade with modified lift coecients simulates the power productions of threewind turbines from these airfoils. The comparisons of the boundary layer characteristics, sectionalforces, and inflow angle of the blade sections are calculated. The k-omega SST turbulence model inOpenFoam visualizes the stall and separation of the blades&rsquo, 2D section. The airfoils with a roundedleading edge show a reduced stall and separated flow region. The power production is 2.3 timeshigher for the airfoil constructed with a more rounded leading edge S809r and two times higher forthe airfoil S809gx of the symmetric structure.

Published
2020

63. Performance analysis of a h-darrieuswind turbine for a series of 4-digit NACA airfoils

Author

Rogowski, Krzysztof, Hansen, Martin Otto Laver, Bangga, Galih, Rogowski, Krzysztof, Hansen, Martin Otto Laver, and Bangga, Galih

Abstract

The purpose of this paper is to estimate the H-Darrieus wind turbine aerodynamic performance, aerodynamic blade loads, and velocity profiles downstream behind the rotor. The wind turbine model is based on the rotor designed by McDonnell Aircraft Company. The model proposed here consists of three fixed straight blades; in the future, this model is planned to be developed with controlled blades. The study was conducted using the unsteady Reynolds averaged Navier-Stokes (URANS) approach with the k-ω shear stress transport (SST) turbulence model. The numerical two-dimensional model was verified using two other independent aerodynamic approaches: A vortex model and the extended version of the computational fluid dynamics (CFD) code FLOWer. All utilized numerical codes gave similar result of the instantaneous aerodynamic blade loads. In addition, steady-state calculations for the applied airfoils were also made using the same numerical model as for the vertical axis wind turbine (VAWT) to obtain lift and drag coefficients. The obtained values of lift and drag force coefficients, for a Reynolds number of 2.9 million, agree with the predictions of the experiment and XFOIL over a wide range of angle of attack. A maximum rotor power coefficient of 0.5 is obtained, which makes this impeller attractive from the point of view of further research. Research has shown that, if this rotor were to work with fixed blades, it is recommended to use the NACA 1418 airfoil instead of the original NACA 0018.

Published
2020

66. Wind Turbine Aerodynamics Modeling Using CFD Approaches

Author

Bangga, Galih and Bangga, Galih

Abstract

As countries seek clean, renewable, low-cost, domestic alternatives to fossil fuels, wind energy is an increasingly important source of power generation worldwide. Scientists and industry professionals require better tools to understand and expand the performance and efficiency. Wind Turbine Aerodynamics Modeling Using CFD Approaches provides a comprehensive and focused introduction to computational approaches for wind turbine aerodynamic calculations, ranging from the simple cost-efficient engineering modeling to high fidelity computational fluid dynamics methods. This broad-reaching book: • Provides a thorough introduction to numerical methods as applied to the simulation of wind turbine aerodynamics • Includes a comprehensive and focused introduction to computational approaches for wind turbines • Provides state-of-the-art information serving as a primer for deeper study The book is an ideal first text for students, researchers, and industry professionals working in wind engineering and in wind energy computations.

Published
2022

87. Responses of vertical axis wind turbines to gusty winds.

Author

Wu, Zhenlong, Wang, Qiang, Bangga, Galih, and Huang, Hao

Subjects
VERTICAL axis wind turbines, WIND turbines, WEATHER
Abstract

Gust is a common atmospheric condition encountered by wind turbines. Despite the presence of a vast amount of literature on this topic, few of them involve lateral gust influence. Due to this motivation, this paper presents an investigation on the effects of sinusoidal gusts on a three-bladed vertical axis wind turbine under varying gust parameters including gust direction, velocity amplitude, and frequency. The chimera mesh technique is used to model the real rotation of the rotor, as well as the resolved gust approach model in the DLR (German Aerospace Center) TAU code for gust simulation. Both the general aerodynamic computational fluid dynamics model and the gust model are validated before the following simulations. Numerous new flow phenomena and physics are revealed. The influences of gust on the rotor power output and flowfield characteristics are discussed and analyzed in detail. The findings in this study may be helpful for some practical wind engineering applications, such as atmospheric influence evaluation and field site selection. [ABSTRACT FROM AUTHOR]

Published
2021
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88. Low-Frequency Oscillation Mitigation usin an Optimal Coordination of CES and PSS based on BA

Author

Lastomo, Dwi, primary, Setiadi, Herlambang, additional, Bangga, Galih, additional, Farid, Imam Wahyudi, additional, Faisal, Muhammad, additional, Hutomo, Peter Go, additional, Syawitri, Taurista Perdana, additional, Putra, Louis, additional, Hendranata, Yongki, additional, Stefanus, Kristiadi, additional, Chairunnisa, Chairunnisa, additional, Ashfahani, Andri, additional, and Sabila, Ahmad, additional

Published
2018
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92. Enhancing BEM simulations of a stalled wind turbine using a 3D correction model

Author

Bangga, Galih, primary, Hutomo, Go, additional, Syawitri, Taurista, additional, Kusumadewi, Tri, additional, Oktavia, Winda, additional, Sabila, Ahmad, additional, Setiadi, Herlambang, additional, Faisal, Muhamad, additional, Hendranata, Yongki, additional, Lastomo, Dwi, additional, Putra, Louis, additional, Kristiadi, Stefanus, additional, and Bumi, Ilmi, additional

Published
2018
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93. Improving a two-equation eddy-viscosity turbulence model to predict the aerodynamic performance of thick wind turbine airfoils

Author

Bangga, Galih, primary, Kusumadewi, Tri, additional, Hutomo, Go, additional, Sabila, Ahmad, additional, Syawitri, Taurista, additional, Setiadi, Herlambang, additional, Faisal, Muhamad, additional, Wiranegara, Raditya, additional, Hendranata, Yongki, additional, Lastomo, Dwi, additional, Putra, Louis, additional, and Kristiadi, Stefanus, additional

Published
2018
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