Aerodynamic and structural evaluation of horizontal axis wind turbines with rated power over 1 MW

An aeromechanical evaluation of large (over 1 Mw of nominal power) Horizontal Axis Wind Turbines (HAWT’s) is performed is this paper. The strategy is based on the combination of an aerodynamic module, which provides the three-dimensional pressure distribution on the HAWT’s blades, an a structural module which takes such pressure forces as input data in order to compute both, blade deformation and strain and stress distributions over the blade. The aerodynamic module combines the three-dimensional nonlinear lifting surface theory approach, which provides the effective incident velocity and angle of attack at each blade section, and a two-dimensional panel method for steady axisymmetric flow in order to obtain the 3D pressure distribution on the blade. Such pressure distribution constitutes the input data for the structural module, which is a finite element package whose output is the blade deformation and strain and stress distribution along the blade, as well as material induced fatigue. This methodology is applied to study a 50 m long blade able to provide a nominal power of 3 Mw. Key words: Wind turbine, aerodynamics, structural behaviour, numerical simulation, efficiency.Primera edició

Computational study of transient flow around Darrieus type cross flow water turbines

This study presents full transient numerical simulations of a cross-flow vertical-axis marine current turbine (straight-bladed Darrieus type) with particular emphasis on the analysis of hydrodynamic characteristics. Turbine design and performance are studied using a time-accurate Reynolds-averaged Navier–Stokes commercial solver. A physical transient rotor-stator model with a sliding mesh technique is used to capture changes in flow field at a particular time step. A shear stress transport k-ω turbulence model was initially employed to model turbulent features of the flow. Two dimensional simulations are used to parametrically study the influence of selected geometrical parameters of the airfoil (camber, thickness, and symmetry-asymmetry) on the performance prediction (torque and force coefficients) of the turbine. As a result, torque increases with blade thickness-to-chord ratio up to 15% and camber reduces the average load in the turbine shaft. Additionally, the influence of blockage ratio, profile trailing edge geometry, and selected turbulence models on the turbine performance prediction is investigate

Hydraulic and rotor-dynamic interaction for performance evaluation on a francis turbine

This paper proposes a new methodology to evaluate the technical state of a Francis turbine installed in a hydroelectric plant by coupling computational fluid dynamics (CFD) and rotor-dynamic analysis. CFD simulations predicted the hydraulic performance of the turbine. The obtained field forces, due to the fluid-structure interaction over the blades of the runner, were used as boundary condition in the shaft rotor-dynamic numerical model, which accurately predicted the dynamic behavior of the turbine’s shaft. Both numerical models were validated with in situ experimental measurements. The CFD model was validated measuring the pressure fluctuations near the rotor–stator interaction area and the torque and radial force in the shaft using strain gages. The rotor-dynamic model was validated using accelerometers installed over the bearings supporting the shaft. Results from both numerical models were in agreement with experimental measurements and provided a full diagnose of the dynamic working condition of the principal systems of the turbine. Implementation of this methodology can be applied to further identify potential failure and improve future design

Simulación numérica del flujo en turbomáquinas hidráulicas. Estado del arte y fuentes de error. Aplicación a turbinas francis

Este artículo contextualiza el papel de la metodología de simulación numérica, Dinámica de Fluidos Computacional (CFD por sus siglas en inglés), como herramienta fundamental de apoyo en el proceso de diseño, optimización y análisis de turbomáquinas hidráulicas. Además de presentar una revisión del estado del arte en este campo, considerando tanto procesos estacionarios como no estacionarios, se discuten las fuentes de error, de modelado y numéricas, presentes en la simulación numérica de turbomáquinas hidráulicas. También se hace hincapié en las diferentes estrategias de modelado posibles así como en sus ventajas e inconvenientes, las cuales se ilustran en el caso particular de las turbinas Francis

Simulación numérica del flujo en turbomáquinas hidráulicas. Estado del arte y fuentes de error. Aplicación a turbinas francis

This article puts into context the role of the methodology of numerical simulation, Computational Fluid Dynamic (CFD), as the basic supporting tool in the design, optimization and analysis of hydraulic turbo machines process. Besides presenting a review of the state of art in this field, taking into account both steady and unsteady processes, sources of error, both modeling and numerical ones, found in the numerical simulation of hydraulic turbo machines are discussed. The different possible modeling strategies as well as their advantages and disadvantages, which are illustrated in the particular case of Francis Turbines, are also emphasized.Este artículo contextualiza el papel de la metodología de simulación numérica, Dinámica de Fluidos Computacional (CFD por sus siglas en inglés), como herramienta fundamental de apoyo en el proceso de diseño, optimización y análisis de turbomáquinas hidráulicas. Además de presentar una revisión del estado del arte en este campo, considerando tanto procesos estacionarios como no estacionarios, se discuten las fuentes de error, de modelado y numéricas, presentes en la simulación numérica de turbomáquinas hidráulicas. También se hace hincapié en las diferentes estrategias de modelado posibles así como en sus ventajas e inconvenientes, las cuales se ilustran en el caso particular de las turbinas Francis

Diseño, construcción y validación de componentes estructurales de una aeronave liviana categoría VLA para su uso en aspersión aérea

This paper presents the calculation, design, simulation, and validation of structural components of the light aircraft prototype CVAC-001 category VLA for use in aerial spraying. The regulation established by the EASA-ADOA (Alternative Design Organization Approval) was defined in the project as an aircraft design model to achieve its guarantee or assurance. For the calculation, design, simulation, and validation process of the structural components, two sides of the load frame and the set of three components that make it up were chosen. The finite element simulation for the static study of stress and buckling and the validation tests of the load frame allows us to conclude that the design feasibility criterion is met for the analyzed components.Este artículo presenta el cálculo, diseño, simulación y validación de los componentes estructurales del prototipo de la aeronave liviana CVAC-001 categoría VLA para uso en aspersión aérea. La reglamentación establecida por la EASA-ADOA (Alternative Design Organization Approval) se definió en el proyecto como modelo de diseño del prototipo de la aeronave para lograr su garantía o aseguramiento. Para el proceso de cálculo, diseño, simulación y validación de los componentes estructurales, se escogieron dos lados de la cuaderna de carga y el conjunto de los tres componentes que la conforman. La simulación por elementos finitos para el estudio estático de esfuerzos, pandeo y los ensayos de validación de la cuaderna de carga permiten concluir que para los componentes analizados se cumple el criterio de factibilidad de diseño

Diseño aeromecánico de aerogeneradores de eje horizontal

Trabajo de grado (Ingeniero Mecánico)-- Universidad Autónoma de Occidente. Facultad de Ingenierías, 2005PregradoIngeniero(a) Mecánico(a

Diseño aeromecánico de aerogeneradores de eje horizontal

Trabajo de grado (Ingeniero Mecánico)-- Universidad Autónoma de Occidente. Facultad de Ingenierías, 200

Derivation and validation of a hard-body particle-wall collision model for non-spherical particles of arbitrary shape

In this work an extended three-dimensional model to describe the process of wall collisions of arbitrary shaped non-spherical particles is developed. This model is derived as the generalized solution of the hard-sphere wall collision model described in Crowe et al. (2012) [1]. The validation of the new model is performed versus experimental results of the collision between cylindrical particles and a flat plate ((Sommerfeld et al., 2015 [2]), Sommerfeld and Lain (2018) [3]). The agreement between the measurements of linear normal and tangential velocities and the model predictions was found to be very good while the rotational velocities forecasted by the model showed also a satisfactory agreement with the experiments

Modelling the Wall Collision of Regular Non-Spherical Particles and Experimental Validation

The importance of numerical calculations (CFD) for supporting the optimization and lay-out of industrial processes involving multiphase flows is continuously increasing. Numerous processes in powder technology involve wall-bounded gas-solid flows where wall collisions essentially affect the process performance. In modelling the particle wall-collision process in the frame of numerical computations the general assumption is that the particles are spherical. However, in most practical situations one is dealing with irregular non-spherical particles or particles with a certain shape, such as granulates or fibers. In the case of non-spherical particle-wall collisions in confined flows, additional parameters such as roughness, particle shape and orientation play an important role and may strongly affect the transport behavior. The change of linear and angular velocity of the particle depends on these parameters, specifically the orientation and the radius of impact of the particle