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Olivier Cleynen

Bio: Olivier Cleynen is an academic researcher from Otto-von-Guericke University Magdeburg. The author has contributed to research in topics: Computational fluid dynamics & Turbine. The author has an hindex of 4, co-authored 13 publications receiving 54 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the effect of flexible structures in a highly dynamic flow regime including separation and stall is studied systematically in an experimental setup which permits observations of all regimes ranging from quasi-static state up to the occurrence of deep dynamic stall and beyond.

25 citations

Journal ArticleDOI
03 Jul 2018
TL;DR: In this article, the characteristics of a vortex power plant integrated in a weir were investigated using computational fluid dynamics, with a special focus on all flow properties relevant to fish migration.
Abstract: The characteristics of a vortex power plant integrated in a weir have been investigated using computational fluid dynamics, with a special focus on all flow properties relevant to fish migration an...

19 citations

Journal ArticleDOI
27 Jan 2021-Energies
TL;DR: In this paper, the authors developed a validated numerical model of a water vortex power plant that serves as a digital twin for further studies such as assessments of the ethohydraulic characteristics or the performance of such devices.
Abstract: The objective of the present paper is to develop a validated numerical model of a water vortex power plant that serves as a digital twin for further studies such as assessments of the ethohydraulic characteristics or the performance of such devices. The reference for the validation process is a large-scale hydraulic installation equipped with a full-scale water vortex power plant prototype installed in Dresden (Germany), where flow field measurements were carried out using three-dimensional Acoustic Doppler Velocimetry. The numerical model was implemented within the software package Star-CCM+. The unsteady, two-phase flow was solved with the Reynolds-Averaged Navier–Stokes equations in a Eulerian Multiphase approach, deploying a Volume of Fluid method to describe the free-surface flow. Water level and flow velocities were systematically compared in key areas of the device, demonstrating that the simulation is in good agreement with experimental observations. Relative differences are limited to at most 4% regarding water height in the system, and even the much more challenging velocity fields are reproduced with typical relative errors of roughly 10%. This validates the ability of the model to model the challenging flow conditions found in a water vortex power plant, enabling subsequent studies of the characteristics of this power plant concerning fish migration.

10 citations

Journal ArticleDOI
TL;DR: In this paper, a bioinspired approach with hyperflexible turbine blades is proposed to reduce flow separation and stall in a passive manner, which results in higher efficiency and increased turbine lifetime through decreased structural loads.
Abstract: State-of-the-art technologies for wind and tidal energy exploitation focus mostly on axial turbines. However, cross-flow hydrokinetic tidal turbines possess interesting features, such as higher area-based power density in array installations and shallow water, as well as a generally simpler design. Up to now, the highly unsteady flow conditions and cyclic blade stall have hindered deployment at large scales because of the resulting low single-turbine efficiency and fatigue failure challenges. Concepts exist which overcome these drawbacks by actively controlling the flow, at the cost of increased mechatronical complexity. Here, we propose a bioinspired approach with hyperflexible turbine blades. The rotor naturally adapts to the flow through deformation, reducing flow separation and stall in a passive manner. This results in higher efficiency and increased turbine lifetime through decreased structural loads, without compromising on the simplicity of the design.

10 citations

Journal ArticleDOI
TL;DR: In this paper, the performance of open-channel hydropower devices can be optimized by maximizing the product of their load, hydraulic, and generator efficiencies using a one-dimensional flow model.
Abstract: The performance of open-channel hydropower devices can be optimized by maximizing the product of their load, hydraulic, and generator efficiencies. The maximum hydraulic power theoretically available must be defined according to the operational scenario retained for the device of interest. In the case of a device operating within a wide, unobstructed channel, the existence of a maximum hydraulic power and the operating speed required to reach it are first predicted using a one-dimensional flow model. This model is then extended to account for the effect of device ducting. As a result, given the available surface level drop and a single duct characteristic parameter, the model predicts the optimum device operating speed, whether the duct can improve performance, and the relative duct size which maximizes the installation’s power density, all at a very low computational cost.

8 citations


Cited by
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Journal Article
TL;DR: In this article, a fast Fourier transform method of topography and interferometry is proposed to discriminate between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour generation techniques.
Abstract: A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

3,742 citations

01 Jan 2002
TL;DR: In this article, the aerodynamic design and performance of VAWTs based on the Darrieus concept is discussed, as well as future trends in design and the inherent socioeconomic and environmental friendly aspects of wind energy as an alternate source of energy.
Abstract: Wind energy is the fastest growing alternate source of energy in the world since its purely economic potential is complemented by its great positive environmental impact. The wind turbine, whether it may be a Horizontal-Axis Wind Turbine (HAWT) or a Vertical-Axis Wind Turbine (VAWT), offers a practical way to convert the wind energy into electrical or mechanical energy. Although this book focuses on the aerodynamic design and performance of VAWTs based on the Darrieus concept, it also discusses the comparison between HAWTs and VAWTs, future trends in design and the inherent socio-economic and environmental friendly aspects of wind energy as an alternate source of energy.

549 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed an optimal shape of the concave and convex sides of a hydraulic Savonius turbine to maximize the output power of the turbine by modifying the blade profile.

84 citations

Journal ArticleDOI
TL;DR: In this paper, experimental, theoretical and numerical data on stream water wheels were systematically collected from literature and analyzed, focusing especially on wheel dimensions, supporting structures, blades and speed, and more light on their hydraulic behavior was shed, adopting the previous classification for a better explanation and understanding.

50 citations

Journal ArticleDOI
15 Dec 2019-Energy
TL;DR: In this paper, an optimization procedure for the shape and position of a thick deflector plate in front of a hydraulic Savonius turbine to improve the output power of the system for a constant frontal area is described.

44 citations