scholarly journals Assessment of a Hydrokinetic Energy Converter Based on Vortex-Induced Angular Oscillations of a Cylinder

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 717
Author(s):  
Iro Malefaki ◽  
Efstathios Konstantinidis

Vortex-induced oscillations offer a potential means to harness hydrokinetic energy even at low current speeds. In this study, we consider a novel converter where a cylinder undergoes angular oscillations with respect to a pivot point, in contrast to most previous configurations, where the cylinder undergoes flow-induced oscillations transversely to the incident free stream. We formulate a theoretical model to deal with the coupling of the hydrodynamics and the structural dynamics, and we numerically solve the resulting nonlinear equation of cylinder motion in order to assess the performance of the energy converter. The hydrodynamical model utilizes a novel approach where the fluid forces acting on the oscillating cylinder are split into components acting along and normal to the instantaneous relative velocity between the moving cylinder and the free stream. Contour plots illustrate the effects of the main design parameters (in dimensionless form) on the angular response of the cylinder and the energy efficiency of the converter. Peak efficiencies of approximately 20% can be attained by optimal selection of the main design parameters. Guidelines on the sizing of actual converters are discussed.

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 125
Author(s):  
Martino Colonna ◽  
Benno Zingerle ◽  
Maria Federica Parisi ◽  
Claudio Gioia ◽  
Alessandro Speranzoni ◽  
...  

The optimization of sport equipment parts requires considerable time and high costs due to the high complexity of the development process. For this reason, we have developed a novel approach to decrease the cost and time for the optimization of the design, which consists of producing a first prototype by 3D printing, applying the forces that normally acts during the sport activity using a test bench, and then measuring the local deformations using 3D digital image correlation (DIC). The design parameters are then modified by topological optimization and then DIC is performed again on the new 3D-printed modified part. The DIC analysis of 3D-printed parts has shown a good agreement with that of the injection-molded ones. The deformation measured with DIC are also well correlated with those provided by finite element method (FEM) analysis, and therefore DIC analysis proves to be a powerful tool to validate FEM models.


2008 ◽  
Vol 130 (10) ◽  
Author(s):  
Michèle Guingand ◽  
Didier Remond ◽  
Jean-Pierre de Vaujany

This paper deals with face gear design. The goal is to propose a simple formula for predicting the width of the wheel as a function of the main design parameters. A specific software was used to achieve this goal. This numerical tool is able to simulate the geometry and the quasistatic loaded behavior of a face gear. The statistical method used for analyzing the influence of data is described: The design of experiments leads to a simple regression model taking into account the influential parameters and their couplings. In the last part of this paper, the results of the formulas are compared to those of the software and an optimal design is proposed based on the regression model.


2011 ◽  
Vol 11 (2) ◽  
pp. 2356-2366 ◽  
Author(s):  
S. Ekinci ◽  
U.B. Celebi ◽  
M. Bal ◽  
M.F. Amasyali ◽  
U.K. Boyaci

2021 ◽  
pp. 69-77
Author(s):  
Boris Alexeevich Arzhannikov ◽  
◽  
Alexander Viktorovich Paranin ◽  

At development of common concept of current collection for three-phase traction power supply system there is the need to select and substantiate main design parameters of catenary suspension. For this purpose, the authors have carried out analytical calculations and developed a numerical mathematical model that allows assessing catenary statics and it’s dynamics in interaction with current collector. On the basis of results of modeling, the authors have substantiated and selected all the required parameters. In particular, they have determined the permissible speed of trains and maximal length of catenary spans.


2014 ◽  
Vol 1016 ◽  
pp. 365-369 ◽  
Author(s):  
Pedro Albuquerque ◽  
Pedro Gamboa ◽  
Miguel Silvestre

The present work describes an aircraft design methodology that uses the wingspan and its mean aerodynamic chord as main design parameters. In the implemented tool, low fidelity models have been developed for the aerodynamics, stability, propulsion, weight, balance and flight performance. A Fortran® routine that calculates the aircraft performance for the user defined mission and vehicle’s performance requirements has been developed. In order to demonstrate this methodology, the results for a case study using the design specifications of the Air Cargo Challenge 2013 are shown.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Katarina Yuen ◽  
Senad Apelfröjd ◽  
Mats Leijon

At Uppsala University, a research group is investigating a system for converting the power in freely flowing water using a vertical-axis turbine directly connected to a permanent magnet generator. An experimental setup comprising a turbine, a generator, and a control system has been constructed and will be deployed in the Dalälven river in the town of Söderfors in Sweden. The design, construction, simulations, and laboratory tests of the control system are presented in this paper. The control system includes a startup sequence for the turbine and load control. These functions have performed satisfactorily in laboratory tests. Simulations of the system show that the power output is not maximized at the same tip-speed ratio as that which maximizes the turbine power capture.


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