The Inverse Vortex Wake Model: A Measurement Analysis Tool

2007 ◽  
Author(s):  
Wouter Haans ◽  
Gijs van Kuik ◽  
Gerard van Bussel
Keyword(s):  
Analysis Tool ◽  
Vortex Wake ◽  
Measurement Analysis ◽  
Wake Model

The Inverse Vortex Wake Model: A Measurement Analysis Tool

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Wouter Haans ◽  
Gijs van Kuik ◽  
Gerard van Bussel
Keyword(s):  
Wind Tunnel ◽  
Analysis Tool ◽  
Vortex Wake ◽  
Flow Conditions ◽  
Rotor Wake ◽  
Rotor Aerodynamics ◽  
Measurement Analysis ◽  
Wake Model ◽  
Induced Velocity ◽  
Blade Loads

To reduce the level of uncertainty associated with current rotor aerodynamics codes, improved understanding of rotor aerodynamics is required. Wind tunnel measurements on model rotors contribute to advancing our knowledge on rotor aerodynamics. The combined recording of blade loads and rotor wake is desired, because of the coupled blade and wake aerodynamics. In general, however, the small size of model rotors prohibits detailed blade load measurements; only the rotor wake is recorded. To estimate the experimental blade flow conditions, a measurement analysis tool is developed: the inverse vortex wake model. The rotor wake is approximated by a lifting line model, using rotor wake measurements to reconstruct the vortex wake. Conservation of circulation, combined with the Biot–Savart law, allows the induced velocity to be expressed in terms of the bound circulation. The unknown bound circulation can be solved for, since the velocity is known from rotor wake measurements. The inverse vortex wake model is subsequently applied to measurements on the near wake of a model rotor subject to both axial and yawed flow conditions, performed at a TUDelft open jet wind tunnel. The inverse vortex wake model estimates the unsteady experimental blade flow conditions and loads that otherwise would have remained obscured.

Benchmarking of a Free Vortex Wake Model for Prediction of Wake Interactions

2019 ◽  
Vol 136 ◽  
pp. 607-620 ◽  
Author(s):  
Kelsey Shaler ◽  
Krista M. Kecskemety ◽  
Jack J. McNamara
Keyword(s):  
Vortex Wake ◽  
Free Vortex ◽  
Wake Interactions ◽  
Wake Model

Modeling Dynamic Stall for a Free Vortex Wake Model

2015 ◽  
Vol 39 (6) ◽  
pp. 675-691 ◽  
Author(s):  
Evan M. Gaertner ◽  
Matthew A. Lackner
Keyword(s):  
Dynamic Stall ◽  
Vortex Wake ◽  
Free Vortex ◽  
Wake Model

scholarly journals An Analysis Tool for the Conceptual Design of High-Lift Systems

2021 ◽  
Author(s):  
William J.M. Bissonnette
Keyword(s):  
Conceptual Design ◽  
Analysis Tool ◽  
High Lift ◽  
Induced Drag ◽  
Multiple Data ◽  
Robust Model ◽  
Conceptual Design Phase ◽  
Wake Interactions ◽  
Wake Model ◽  
The Impact

An aerodynamic analysis tool for the conceptual design of high-lift devices has been developed. The method employs a higher-order potential ow method that uses elements of distributed vorticity. The subsequent numerically robust model allows for strong wake interactions, even when using a relaxed wake. The method predicts lift and induced drag values that compare well with multiple data experiments, and, when implemented in a panel code, maximum lift predictions of a high-lift system are found with an error of 6% from experimental data. This method is used to assess the impact that various wake models have on lift and induced drag predictions. This study shows that significant errors can be introduced when employing a prescribed wake model set to extreme angles. Compared to an approach using CFD, the computational expense of these models is relatively low. A single analysis requires minutes, making these models suitable for the iterative conceptual design phase

scholarly journals Aeroelastic loads on a 10 MW turbine exposed to extreme events selected from a year-long large-eddy simulation over the North Sea

2021 ◽  
Vol 6 (4) ◽  
pp. 983-996
Author(s):  
Gerard Schepers ◽  
Pim van Dorp ◽  
Remco Verzijlbergh ◽  
Peter Baas ◽  
Harmen Jonker
Keyword(s):  
Large Eddy Simulation ◽  
North Sea ◽  
Extreme Events ◽  
Vortex Wake ◽  
Free Vortex ◽  
Eddy Simulation ◽  
The North ◽  
Large Eddy ◽  
The North Sea ◽  
Wake Model

Abstract. In this article the aeroelastic loads on a 10 MW turbine in response to extreme events (low-level jet, shear, veer and turbulence intensity) selected from a year-long large-eddy simulation (LES) on a site at the North Sea are evaluated. These events are generated with a high-fidelity LES wind model and fed into an aeroelastic tool using two different aerodynamic models: a model based on blade element momentum (BEM) and a free vortex wake model. Then the aeroelastic loads are calculated and compared with the loads from the IEC standards. It was found that the loads from all these events remain within those of the IEC design loads. Moreover, the accuracy of BEM-based methods for modelling such wind conditions showed a considerable overprediction compared to the free vortex wake model for the events with extreme shear and/or veer.

Unsteady Hydrofoils: Theoretical and Computational Analysis

2013 ◽  
Author(s):  
Daniel T. Valentine
Keyword(s):  
Flat Plate ◽  
Computational Analysis ◽  
Vortex Sheet ◽  
Vortex Wake ◽  
Two Dimensional ◽  
Fixed Angle ◽  
Induced Drag ◽  
Wake Model ◽  
Theoretical Results ◽  
Computational Predictions

In this paper the computational problem examined is the impulsive start of a two-dimensional flat-plate hydrofoil at a fixed angle of attack. The method applied is an equally-spaced lumped-vortex panel method. The results from a lumped-vortex wake model and a shed-vortex sheet wake model are reported. Comparisons with the linear theory of Wagner (1925), the theoretical results associated with the single lumped-vortex wake model and the full wake model are presented. In addition, it is shown that the computational predictions are consistent with results reported by Katz and Plotkin (2001); they applied a distribution of vortices to model the wake. In the present paper the importance of resolving the chordwise pressure distribution in unsteady hydrofoil problems is elucidated. New predictions of both the evolution of lift and induced drag are reported for the instantaneously started flat plate. The computational predictions are compared with theorecticalpredictions also discussed in this paper.

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