Wind tunnel ≈ Wind tunnel
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Experimental and theoretical study of wind turbine wakes in yawed conditions Open
This work is dedicated to systematically studying and predicting the wake characteristics of a yawed wind turbine immersed in a turbulent boundary layer. To achieve this goal, wind tunnel experiments were performed to characterize the wake…
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Flow Structure and Turbulence in Wind Farms Open
Similar to other renewable energy sources, wind energy is characterized by a low power density. Hence, for wind energy to make considerable contributions to the world's overall energy supply, large wind farms (on- and offshore) consisting …
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CFD simulation of outdoor ventilation of generic urban configurations with different urban densities and equal and unequal street widths Open
Outdoor ventilation is very important for a healthy and livable urban environment. It is strongly influenced by wind speed and direction, which in turn are affected by urban morphology. This paper first provides a detailed review of the li…
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Wake structure in actuator disk models of wind turbines in yaw under uniform inflow conditions Open
Reducing wake losses in wind farms by deflecting the wakes through turbine yawing has been shown to be a feasible wind farm controls approach. Nonetheless, the effectiveness of yawing depends not only on the degree of wake deflection but a…
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Comparison of wind farm large eddy simulations using actuator disk and actuator line models with wind tunnel experiments Open
We compare wind farm large eddy simulations with the EPFL wind tunnel measurement by Chamorro and Porté-Agel (Bound-Lay. Meteorol. 136, 515 (2010) and Energies 4, 1916 (2011)). We find that the near turbine wake, up to 3 turbine diameters …
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A critical comparison of Lagrangian methods for coherent structure detection Open
We review and test twelve different approaches to the detection of finite-time coherent material structures in two-dimensional, temporally aperiodic flows. We consider both mathematical methods and diagnostic scalar fields, comparing their…
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Optical Fiber Sensors for Aircraft Structural Health Monitoring Open
Aircraft structures require periodic and scheduled inspection and maintenance operations due to their special operating conditions and the principles of design employed to develop them. Therefore, structural health monitoring has a great p…
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Wind farm power optimization via yaw angle control: A wind tunnel study Open
Yaw angle control is known nowadays as a promising and effective technique to mitigate wake effects in wind farms. In this paper, we perform wind tunnel experiments to study the performance of a model wind farm with five turbine rows under…
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Shark skin-inspired designs that improve aerodynamic performance Open
There have been significant efforts recently aimed at improving the aerodynamic performance of aerofoils through the modification of their surfaces. Inspired by the drag-reducing properties of the tooth-like denticles that cover the skin o…
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The aerodynamics of the curled wake: a simplified model in view of flow control Open
When a wind turbine is yawed, the shape of the wake changes and a curled wake profile is generated. The curled wake has drawn a lot of interest because of its aerodynamic complexity and applicability to wind farm controls. The main mechani…
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CFD and wind-tunnel analysis of outdoor ventilation in a real compact heterogeneous urban area: Evaluation using “air delay” Open
Outdoor urban ventilation in a real complex urban area is investigated by introducing a new ventilation indicator – the “air delay”. Computational Fluid Dynamics (CFD) simulations are performed using the 3D steady Reynolds-Averaged Navier-…
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On the use of helium-filled soap bubbles for large-scale tomographic PIV in wind tunnel experiments Open
The flow-tracing fidelity of sub-millimetre diameter helium filled soap bubbles (HFSB) for low speed aerodynamics is studied. The main interest of using HFSB in relation to micron-size droplets is the large amount of scattered light, enabl…
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Bioinspired morphing wings for extended flight envelope and roll control of small drones Open
Small-winged drones can face highly varied aerodynamic requirements, such as high manoeuvrability for flight among obstacles and high wind resistance for constant ground speed against strong headwinds that cannot all be optimally addressed…
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CFD simulation of cross-ventilation in buildings using rooftop wind-catchers: Impact of outlet openings Open
© 2017 The Authors Cross-ventilation using rooftop wind-catchers is very complex as it is influenced by a wide range of interrelated factors including aerodynamic characteristics of the wind catcher, approach-flow conditions and building g…
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Wind tunnel testing of a closed-loop wake deflection controller for wind farm power maximization Open
This paper presents results from wind tunnel tests aimed at evaluating a closed- loop wind farm controller for wind farm power maximization by wake deflection. Experiments are conducted in a large boundary layer wind tunnel, using three se…
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Control-oriented model for secondary effects of wake steering Open
This paper presents a model to incorporate the secondary effects of wake steering in large arrays of turbines. Previous models have focused on the aerodynamic interaction of wake steering between two turbines. The model proposed in this pa…
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A simulation study demonstrating the importance of large-scale trailing vortices in wake steering Open
In this paper, we investigate the role of flow structures generated in wind farm control through yaw misalignment. A pair of counter-rotating vortices is shown to be important in deforming the shape of the wake and in explaining the asymme…
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Wind tunnel study of the wind turbine interaction with a boundary-layer flow: Upwind region, turbine performance, and wake region Open
Comprehensive wind tunnel experiments were carried out to study the interaction of a turbulent boundary layer with a wind turbine operating under different tip-speed ratios and yaw angles. Force and power measurements were performed to cha…
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How tall buildings affect turbulent air flows and dispersion of pollution within a neighbourhood Open
The city of London, UK, has seen in recent years an increase in the number of high-rise/multi-storey buildings ("skyscrapers") with roof heights reaching 150 m and more, with the Shard being a prime example with a height of ∼310 m. This ch…
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Wind and water tunnel testing of a morphing aquatic micro air vehicle Open
Aerial robots capable of locomotion in both air and water would enable novel mission profiles in complex environments, such as water sampling after floods or underwater structural inspections. The design of such a vehicle is challenging be…
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Experimental parameter study for passive vortex generators on a 30% thick airfoil Open
Passive vane–type vortex generators (VGs) are commonly used on wind turbine blades to mitigate the effects of flow separation. However, significant uncertainty surrounds VG design guidelines. Understanding the influence of VG parameters on…
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Cross-ventilation in a generic isolated building equipped with louvers: Wind-tunnel experiments and CFD simulations Open
Natural ventilation can be used to improve indoor air quality, remove contaminants from spaces and to remove heat from a building during the day, or during the night. In some cases, openings for natural ventilation are equipped with shadin…
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Dual serial vortex-induced energy harvesting system for enhanced energy harvesting Open
This paper presents a novel dual serial vortex-induced vibration energy harvesting system for enhanced energy harvesting. It consists of two identical cantilever-based piezoelectric vortex-induced vibration energy harvesters, which are suc…
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Highly reliable wind-rolling triboelectric nanogenerator operating in a wide wind speed range Open
Triboelectric nanogenerators are aspiring energy harvesting methods that generate electricity from the triboelectric effect and electrostatic induction. This study demonstrates the harvesting of wind energy by a wind-rolling triboelectric …
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A Wake Modeling Paradigm for Wind Farm Design and Control Open
Wake models play an integral role in wind farm layout optimization and operations where associated design and control decisions are only as good as the underlying wake model upon which they are based. However, the desired model fidelity mu…
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Large eddy simulation of aircraft at affordable cost: a milestone in computational fluid dynamics Open
While there have been numerous applications of large eddy simulations (LES) to complex flows, their application to practical engineering configurations, such as full aircraft models, have been limited to date. Recently, however, advances i…
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Common Envelope Wind Tunnel: Coefficients of Drag and Accretion in a Simplified Context for Studying Flows around Objects Embedded within Stellar Envelopes Open
This paper examines the properties of flows around objects embedded within common envelopes in the simplified context of a “wind tunnel.” We establish characteristic relationships between key common envelope flow parameters like the Mach n…
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GADEN: A 3D Gas Dispersion Simulator for Mobile Robot Olfaction in Realistic Environments Open
This work presents a simulation framework developed under the widely used Robot Operating System (ROS) to enable the validation of robotics systems and gas sensing algorithms under realistic environments. The framework is rooted in the pri…
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Aerodynamic interaction between propellers of a distributed-propulsion system in forward flight Open
This article describes an experimental investigation of the aerodynamic interaction that occurs between distributed propellers in forward flight. To this end, three propellers were installed in close proximity in a wind tunnel, and the cha…
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Bioinspired Trailing-Edge Noise Control Open
Strategies for trailing edge noise control have been inspired by the downy canopy that covers the surface of exposed flight feathers of many owl species. Previous wind tunnel measurements demonstrate that canopies of similar characteristic…