Prediction and Analysis of the Nonsteady Transitional Boundary Layer Dynamics for flow over an Oscillating Wind Turbine Airfoil using the γ-Reθ Transition Model

2016 ◽  
Author(s):  
Tarak N. Nandi ◽  
James Brasseur ◽  
Ganesh Vijayakumar
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Transition Model ◽  
Transitional Boundary Layer ◽  
Wind Turbine Airfoil ◽  
Boundary Layer Dynamics

Prediction of laminar, transitional and turbulent flow regimes, based on three-equation k-ω turbulence model

2008 ◽  
Vol 112 (1134) ◽  
pp. 469-476 ◽  
Author(s):  
R. Taghavi-Zenouz ◽  
M. Salari ◽  
M. Etemadi
Keyword(s):  
Boundary Layer ◽  
Kinetic Energy ◽  
Wind Turbine ◽  
Flat Plate ◽  
Turbine Blade ◽  
Wind Turbine Blade ◽  
Freestream Turbulence ◽  
Boundary Layer Flows ◽  
Laminar Separation ◽  
Transitional Boundary Layer

Abstract A recently developed transitional model for boundary-layer flows has been examined on a flat plate and the well-known S809 wind turbine blade. Proposed numerical model tries to simulate streamwise fluctuations, induced by freestream turbulence, in pre-transitional boundary-layer flows by introducing an additional transport equation for laminar kinetic energy term. This new approach can be used for modeling of transitional flows which are exposed to both the freestream turbulence intensity and streamwise pressure gradient, which are known as the most dominant factors in occurrence of transition. Computational method of this model is based on the solution of the Reynolds averaged Navier-Stokes (RANS) equations and the eddy-viscosity concept. The model includes three transport equations of laminar kinetic energy, turbulent kinetic energy and dissipation rate frequency. The present model is capable of predicting either natural or bypass transitional mechanisms, which may occur in attached boundary-layer flows. In addition, the model can simulate transition in the separated free shear layers and the subsequent turbulent re-attachment to form a laminar separation bubble. Flat plate was exposed to different freestream turbulence intensities and streamwise pressure gradients. Wind turbine blade was examined under two different Reynolds numbers, with one of them suitable for the occurrence of laminar separation bubbles on its surfaces. To evaluate the performance of this new model in resolving transitional boundary-layer flows, final results have been compared to those obtained through application of conventional turbulence models. Comparison of final results for the flat plate and the S809 aerofoil with available experimental data show very close agreements.

scholarly journals Wall-Resolved LES Modeling of a Wind Turbine Airfoil at Different Angles of Attack

2020 ◽  
Vol 8 (3) ◽  
pp. 212 ◽  
Author(s):  
Irene Solís-Gallego ◽  
Katia María Argüelles Díaz ◽  
Jesús Manuel Fernández Oro ◽  
Sandra Velarde-Suárez
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Acoustic Waves ◽  
Urban Environments ◽  
Far Field ◽  
Noise Generation ◽  
Noise Propagation ◽  
Trailing Edge ◽  
Wind Turbine Airfoil ◽  
Les Model

Noise has arisen as one of the main restrictions for the deployment of wind turbines in urban environments or in sensitive ecosystems like oceans for offshore and coastal applications. An LES model, adequately planned and resolved, is useful to describe the noise generation mechanisms in wind turbine airfoils. In this work, a wall-resolved LES model of the turbulent flow around a typical wind turbine airfoil is presented and described in detail. The numerical results obtained have been validated with hot wire measurements in a wind tunnel. The description of the boundary layer over the airfoil provides an insight into the main noise generation mechanism, which is known to be the scattering of the vortical disturbances in the boundary layer into acoustic waves at the airfoil trailing edge. In the present case, 2D wave instabilities are observed in both suction and pressure sides, but these perturbations are diffused into a turbulent boundary layer prior to the airfoil trailing edge, so tonal noise components are not expected in the far-field noise propagation. The results obtained can be used as input data for the prediction of noise propagation to the far-field using a hybrid aeroacoustic model.

scholarly journals Numerical simulation of transitional flow on a wind turbine airfoil with RANS-based transition model

2017 ◽  
Vol 18 (9) ◽  
pp. 879-898 ◽  
Author(s):  
Ye Zhang ◽  
Zhengzhong Sun ◽  
Alexander van Zuijlen ◽  
Gerard van Bussel
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Transitional Flow ◽  
Transition Model ◽  
Wind Turbine Airfoil

1310 Boundary Layer Control for Wind Turbine Airfoil Using the Tape

2001 ◽  
Vol 2001 (0) ◽  
pp. 178
Author(s):  
Takashige Inaba ◽  
Hikaru Matsumiya ◽  
Eiji Kato ◽  
Tetsuya Kogaki ◽  
Makoto lida
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Boundary Layer Control ◽  
Wind Turbine Airfoil ◽  
Layer Control

An Improved Boundary Layer Transition Correlation

1992 ◽  
Author(s):  
Ahmad Fasihfar ◽  
Mark W. Johnson
Keyword(s):  
Boundary Layer ◽  
Signal Processing ◽  
Digital Signal ◽  
Boundary Layer Transition ◽  
Transition Model ◽  
Turbulence Level ◽  
Hot Wire ◽  
Layer Transition ◽  
Transitional Boundary Layer ◽  
The Mean

The influence of pressure gradient and freestream turbulence level on boundary layer transition has been studied experimentally using hot wire instrumentation and digital signal processing and analysis. An established transition correlation and recent transition model were found to give acceptable prediction of the experimental results. The digital system was used to conditionally sample the transitional boundary layer data and hence to determine the mean and fluctuating velocity profiles for the laminar and turbulent parts of the boundary layer separately. The turbulent portions were found to correlate well with fully developed turbulent boundary layer profiles, but the laminar portion profiles deviated considerably from those typical of a laminar boundary layer.

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