Navier-Stokes and Comprehensive Analysis Performance Predictions of the NREL Phase VI Experiment

2003 ◽  
Author(s):  
Earl Duque ◽  
Michael Burkland ◽  
Wayne Johnson
Keyword(s):  
Comprehensive Analysis ◽  
Navier Stokes ◽  
Performance Predictions ◽  
Nrel Phase Vi

Navier-Stokes and Comprehensive Analysis Performance Predictions of the NREL Phase VI Experiment

2003 ◽  
Author(s):  
Earl P. N. Duque ◽  
Michael D. Burklund ◽  
Wayne Johnson
Keyword(s):  
Experimental Data ◽  
Wind Turbine ◽  
Turbine Rotor ◽  
Operating Conditions ◽  
Navier Stokes ◽  
Horizontal Axis Wind Turbine ◽  
Performance Predictions ◽  
Nasa Ames Research ◽  
Nrel Phase Vi ◽  
Wind Turbine Rotor

A vortex lattice code, CAMRAD II, and a Reynolds-Averaged Navier-Stoke code, OVERFLOW-D2, were used to predict the aerodynamic performance of a two-bladed horizontal axis wind turbine. All computations were compared with experimental data that was collected at the NASA Ames Research Center 80-by 120-Foot Wind Tunnel. Computations were performed for both axial as well as yawed operating conditions. Various stall delay models and dynamics stall models were used by the CAMRAD II code. Comparisons between the experimental data and computed aerodynamic loads show that the OVERFLOW-D2 code can accurately predict the power and spanwise loading of a wind turbine rotor.

Navier-Stokes and Comprehensive Analysis Performance Predictions of the NREL Phase VI Experiment

2003 ◽  
Vol 125 (4) ◽  
pp. 457-467 ◽  
Author(s):  
Earl P. N. Duque ◽  
Michael D. Burklund ◽  
Wayne Johnson
Keyword(s):  
Operating Conditions ◽  
Dynamic Stall ◽  
Navier Stokes ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Performance Predictions ◽  
Delay Models ◽  
Proper Power ◽  
Nrel Phase Vi ◽  
Lifting Line

A lifting-line code, CAMRAD II, and a Reynolds-Averaged Navier-Stokes code, OVERFLOW-D, were used to predict the aerodynamic performance of a two-bladed horizontal axis wind turbine. All computations were compared with experimental data that was collected at the NASA Ames Research Center 80-by-120-foot Wind Tunnel. Lifting-line computations were performed for both axial and yawed operating conditions while the Navier-Stokes computations were performed for only the axial conditions. Various stall delay models and dynamic stall models were used by the CAMRAD II code. For axial operating conditions, the predicted rotor performance varied significantly, particularly for stalled wind speeds. The lifting-line required the use of stall delay models to obtain the proper stall behavior, yet it still has difficulty in predicting the proper power magnitude in stall. The Navier-Stokes method captures the stall behavior and gives a detailed insight into the fluid mechanics of the stall behavior.

scholarly journals Off-Design Performance Prediction for Radial-Flow Impellers

1988 ◽  
Author(s):  
Shen C. Lee ◽  
Daying Chen
Keyword(s):  
Stokes Equations ◽  
Mechanical Energy ◽  
Navier Stokes ◽  
Shear Stresses ◽  
Pump Impeller ◽  
Navier Stokes Equations ◽  
Measured Velocity ◽  
Production Water ◽  
Performance Predictions ◽  
Stream Functions

A numerical method was developed to consider the two-dimensional flowfield between impeller blades of a given geometry. Solution of the laminar Navier-Stokes equations in geometry-oriented coordinates was obtained for stream functions and vorticities. Velocities and pressures were calculated to determine the output fluid-energy head. The circumferential components of the normal and shear stresses along the blade were evaluated to give the input mechanical-energy head. Performance predictions were obtained for different load conditions. Comparisons were made with the measured velocity vectors of the flowfield of an air-pump impeller and with the measured performance of a production water pump, good agreements were reached.

A Numerical Study on Performances of Centrifugal Compressor Stages With Different Radial Gaps

2000 ◽  
Author(s):  
K. Sato ◽  
L. He
Keyword(s):  
Centrifugal Compressor ◽  
Stokes Equations ◽  
Numerical Study ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Centrifugal Impeller ◽  
Vaned Diffuser ◽  
Navier Stokes Equations ◽  
Performance Predictions ◽  
Radial Gap

A numerical study of 3D unsteady flows in centrifugal compressor stages solving the Navier-Stokes equations is presented. The emphasis is on the effect of the radial gap between blade rows on the aerodynamic performance. In the numerical tests, Krain’s centrifugal impeller was combined with a DCA (Double Circular Arc) type radial vaned diffuser. The compressor stages with three settings of radial gap ranging from 5 to 15 percent of the impeller trailing edge radius are configured and unsteady flow simulations are carried out to compare the time-averaged efficiencies. The performance predictions show that the efficiency is deteriorated if the radial gap between blade rows is reduced with intensified blade row interaction, which is in contradiction to the general trend for axial compressor stages. In the centrifugal compressors tested, wake chopping by diffuser vanes, which usually benefits efficiency in axial compressor stages, causes unfavourable wake compression through the diffuser passages to deteriorate the efficiency.

Detached-Eddy Simulation of Flow Around the NREL Phase-VI Blade

2002 ◽  
Author(s):  
J. Johansen ◽  
N. N. So̸rensen ◽  
J. A. Michelsen ◽  
S. Schreck
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Simulation Model ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Reynolds Averaged Navier Stokes ◽  
Nrel Phase Vi

The Detached-Eddy Simulation model implemented in the computational fluid dynamics code, EllipSys3D, is applied on the flow around the NREL Phase-VI wind turbine blade. Results are presented for flow around a parked blade at fixed angle of attack and a blade pitching along the blade axis. Computed blade characteristics are compared with experimental data from the NREL/NASA Ames Phase-VI unsteady experiment. The Detached-Eddy Simulation model is a method for predicting turbulence in computational fluid dynamics computations, which combines a Reynolds Averaged Navier-Stokes method in the boundary layer with a Large Eddy Simulation in the free shear flow. The present study focuses on static and dynamic stall regions highly relevant for stall regulated wind turbines. Computations do predict force coefficients and pressure distributions fairly good and results using Detached-Eddy Simulation show considerably more three-dimensional flow structures compared to conventional two-equation Reynolds Averaged Navier-Stokes turbulence models, but no particular improvements are seen on the global blade characteristics.

A Parallelized Coupled Navier-Stokes/Vortex-Panel Solver

2005 ◽  
Vol 127 (4) ◽  
pp. 475-487 ◽  
Author(s):  
Sven Schmitz ◽  
Jean-Jacques Chattot
Keyword(s):  
Near Field ◽  
Computational Cost ◽  
Turbulence Models ◽  
Vortex Sheet ◽  
Panel Method ◽  
Navier Stokes ◽  
Attached Flow ◽  
Bladed Rotor ◽  
Nrel Phase Vi ◽  
Good Agreement

A Navier-Stokes solver, CFX V5.6, is coupled with an in-house developed Vortex-Panel method for the numerical analysis of wind turbines. The Navier-Stokes zone is confined to the near-field around one wind turbine blade, the Vortex-Panel method models the entire vortex sheet of a two-bladed rotor and accounts for the far-field. This coupling methodology reduces both numerical diffusion and computational cost. The parallelized coupled solver (PCS) is applied to the NREL Phase VI rotor configuration under no-yaw conditions. Fully turbulent flow is assumed using the k - ϵ and k - ω turbulence models. Results obtained are very encouraging for fully attached flow. For separated and partially stalled flow, results are in good agreement with experimental data. Discrepancies observed between the turbulence models are attributed to different prediction of the onset of separation. This is revealed by two-dimensional (2D) results of the S809 airfoil.

Evaluation of Turbulence Models for the Prediction of Wind Turbine Aerodynamics

2003 ◽  
Author(s):  
Sarun Benjanirat ◽  
Lakshmi N. Sankar ◽  
Guanpeng Xu
Keyword(s):  
Wind Turbine ◽  
Model Development ◽  
Turbulence Models ◽  
Separated Flow ◽  
Equation Model ◽  
Navier Stokes ◽  
Implicit Time ◽  
Horizontal Axis Wind Turbine ◽  
Attached Flow ◽  
Nrel Phase Vi

The performance of the NREL Phase VI horizontal axis wind turbine has been studied with a 3-D unsteady Navier-Stokes solver. This solver is third order accurate in space and second order accurate in time, and uses an implicit time marching scheme. Calculations were done for a range of wind conditions from 7 m/s to 25 m/s where the flow conditions ranged from attached flow to massively separated flow. A variety of turbulence models were studied: Baldwin-Lomax Model, Spalart-Allmaras one-equation model, and k-ε two equations model with and without wall corrections. It was found all the models predicted the normal forces and associated bending moments well, but most of them had difficulties in modeling the chord wise forces, power generation, and pitching moments. It was found that the k-ε model with near wall corrections did the best job of predicting most the quantities with acceptable levels of accuracy. Additional studies aimed at transition model development, and grid sensitivity studies in the tip region are deemed necessary to improve the correlation with experiments.

Sign in / Sign up

Export Citation Format

Share Document