Mesfin Belayneh Ageze
@aait.edu.et
Addis Ababa Institute of Technology
Addis Ababa University
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Solomon Terefe Ayele, Mesfin Belayneh Ageze, Migbar Assefa Zeleke, and Temesgen Abriham Miliket
Elsevier BV
Temesgen Abriham Miliket, Mesfin Belayneh Ageze, Muluken Temesgen Tigabu, and Migbar Assefa Zeleke
Elsevier BV
Temesgen Abriham Miliket, Mesfin Belayneh Ageze, and Muluken Temesgen Tigabu
Informa UK Limited
ABSTRACT The wind is one of the most promising green energy resources that replenishes itselves in less than a human lifetime without depleting the planet’s resources. According to the disposition of the blade concerning the shaft, wind turbine can be classified as horizontal axis wind turbine (HAWT) and vertical axis wind turbine (VAWT). In contrast to VAWT, HAWT covers most commercial installations around the globe. However, VAWTs became a promising alternative for areas far away from grid-connected electricity, they have certain drawbacks associated with aerodynamic performance. The present work overviews the magnitude of factors affecting the aerodynamics of typical VAWT, i.e H-Darrieus VAWT and enhancement options associated with cutting edge performance. Additionally, the accuracy of the turbine performance predicting tools through computational investigation and optimization was also assessed. Therefore, the review covered the factors that altered the turbine performance and viable enhancement options studied in the existing literature. Finally, FSI simulation was tics of materials commonly used for turbine blade manufacturing. It was determined that the computational tools employed significantly influence the accuracy of the model, and proper model selection and more experimental validations are compulsory. It was determined that the computational tools employed significantly influence the accuracy of the model, and proper model selection and more experimental validations are compulsory.
Temesgen Abriham Miliket, Mesfin Belayneh Ageze, and Muluken Temesgen Tigabu
Springer International Publishing
Migbar Assefa Zeleke and Mesfin Belayneh Ageze
Hindawi Limited
The study of heat conduction phenomena using peridynamic (PD) theory has a paramount significance on the development of computational heat transfer. This is because PD theory has got an interesting feature to deal with the inherent nonlocal nature of heat transfer processes. Since the revolutionary work on PD theory by Silling (2000), extensive investigations have been devoted to PD theory. This paper provides a survey on the recent developments of PD theory mainly focusing on diffusion based peridynamic (PD) formulation. Both the bond-based and state-based PD formulations are revisited, and numerical examples of two-dimensional problems are presented.
Mesfin Ageze, Yefa Hu, and Huachun Wu
MDPI AG
The current trends of wind turbine blade designs are geared towards a longer and slender blade with high flexibility, exhibiting complex aeroelastic loadings and instability issues, including flutter; in this regard, fluid-structure interaction (FSI) plays a significant role. The present article will conduct a comparative study between uni-directional and bi-directional fluid-structural coupling models for a horizontal axis wind turbine. A full-scale, geometric copy of the NREL 5MW blade with simplified material distribution is considered for simulation. Analytical formulations of the governing relations with appropriate approximation are highlighted, including turbulence model, i.e., Shear Stress Transport (SST) k-ω. These analytical relations are implemented using Multiphysics package ANSYS employing Fluent module (Computational Fluid Dynamics (CFD)-based solver) for the fluid domain and Transient Structural module (Finite Element Analysis-based solver) for the structural domain. ANSYS system coupling module also is configured to model the two fluid-structure coupling methods. The rated operational condition of the blade for a full cycle rotation is considered as a comparison domain. In the bi-directional coupling model, the structural deformation alters the angle of attack from the designed values, and by extension the flow pattern along the blade span; furthermore, the tip deflection keeps fluctuating whilst it tends to stabilize in the uni-directional coupling model.
Mesfin Belayneh Ageze, Yefa Hu, and Huachun Wu
Hindawi Limited
The interaction of fluid flow and the structure dynamic of the system is a vital subject for machines operating under their coupling. It is not different for wind turbine either, especially as the coupling enhanced for multi-MW turbine with larger and flexible blades and complex control methods, and other nonlinearity, more comprehensive aeroelastic tools will be required to investigate the realistic phenomena. The present paper will overview the aeroelastic tool for wind turbine, the efforts done, gaps, and future directions indicated. One starts with background of the subject, presenting a case study to demonstrate the effect of fluid-structure interaction considering NREL 5MW blade and a brief comparison of several aeroelastic codes. Cutting edge efforts done in the area such as complex inflow, effect of geometric nonlinearity, and other stability and smart control issues are addressed and concluded by elaborating the gaps and future direction of aeroelasticity of wind turbine.