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Your search keyword '"Biadgo Asress Mulugeta"' showing total 2 results
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2 results on '"Biadgo Asress Mulugeta"'

1. Aerodynamic characteristics of high speed train under turbulent cross winds: A numerical investigation using unsteady-RANS method

Author

Biadgo Asress Mulugeta, Simonović Aleksandar, Svorcan Jelena, and Stupar Slobodan

Subjects
cross-wind, high speed trains, computational fluid dynamics, reynolds-averaged navier-stokes equations, k-epsilon turbulence model, numerical analysis, Engineering (General). Civil engineering (General), TA1-2040, Mechanics of engineering. Applied mechanics, TA349-359
Abstract

Increasing velocity combined with reduced mass of modern high speed trains poses the question of influence of strong cross winds on its aerodynamics. Strong cross winds may affect the running stability of high speed trains via the amplified aerodynamic forces and moments. In this study, simulations of turbulent cross wind flows over the leading and end car of ICE-2 high speed train have been performed at different yaw angles The train aerodynamic problems are closely associated with the flows occurring around train. The flow around the train has been considered as incompressible and was obtained by solving the incompressible form of the unsteady Reynolds-Averaged Navier-Stokes (RANS) equations combined with the realizable k-epsilon turbulence model. Important aerodynamic coefficients such as the side force and rolling moment coefficients have been calculated for yaw angles ranging from -30° to 60° and compared to results obtained from wind tunnel tests. The dependence of the flow structure on yaw angle has also been presented.

Published
2014

2. Aerodynamic design of horizontal axis wind turbine blades

Author

Biadgo Asress Mulugeta and Aynekulu Gerawork

Subjects
Airfoil, Chord (aeronautics), Turbine blade, business.industry, Computer science, 020209 energy, Mechanical Engineering, 02 engineering and technology, Aerodynamics, Structural engineering, Turbine, Wind speed, law.invention, Aerodynamic force, Mechanics of Materials, law, 0202 electrical engineering, electronic engineering, information engineering, Torque, business
Abstract

Designing horizontal axis wind turbine (HAWT) blades to achieve satisfactory levels of performance starts with the knowledge of aerodynamic forces acting on the blades. In this paper, a design method based on blade element momentum (BEM) theory is explained for HAWT blades. The method is used to optimize the chord and twist distributions of the blades. Applying this method a 1000W HAWT rotor is designed. A user-interface computer program is written on VISUALBASIC to estimate the aerodynamic performance of the existing HAWT blades and used for the performance analysis of the designed 1000W HAWT rotor. The program gives blade geometry parameters (chord and twist distributions), coefficients of performance and aerodynamic forces (trust and torque) for the following inputs; power required from the turbine, number of blades, design wind velocity and blade profile type (airfoil). The program shows the results with figures. It also gives the three dimensional views of the designed blade elements for visualization after exported to AutoCAD.

Published
2017
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