Presentation is loading. Please wait.

Presentation is loading. Please wait.

CFD Simulation: MEXICO Rotor Wake EWEC: 2009 Andreas Bechmann & Niels Sørensen Risø DTU ∙ National Laboratory for Sustainable Energy

Similar presentations


Presentation on theme: "CFD Simulation: MEXICO Rotor Wake EWEC: 2009 Andreas Bechmann & Niels Sørensen Risø DTU ∙ National Laboratory for Sustainable Energy"— Presentation transcript:

1 CFD Simulation: MEXICO Rotor Wake EWEC: 2009 Andreas Bechmann & Niels Sørensen Risø DTU ∙ National Laboratory for Sustainable Energy andh@risoe.dtu.dk

2 Risø DTU, Technical University of Denmark Outline: 1.Background 2.MEXICO Experiment 3.CFD Simulations 4.Conclusion 17 March 09CFD Simulation of the MEXICO Rotor Wake2

3 Risø DTU, Technical University of Denmark Background 1/3 “Today, siting of wind turbines in wind farms is based on power output considerations” TOPFARM project: Optimization of wind farm topology based on power output and turbine loads. WP1: Internal flow model Model to describe the flow inside the wind farm 17 March 09CFD Simulation of the MEXICO Rotor Wake3

4 Risø DTU, Technical University of Denmark Background 2/3 How to validate the model? 17 March 09CFD Simulation of the MEXICO Rotor Wake4 Wind tunnel Single wind turbine Wind farm

5 Risø DTU, Technical University of Denmark Background 3/3 Objectives: To make a “clean” dataset for validating wake models Method: 1.Extract wake data from the MEXICO experiment 2.Compare measurements with high resolution CFD 3.Combine measurements and CFD results in a dataset for validating wake models 17 March 09CFD Simulation of the MEXICO Rotor Wake5 Wind tunnel The MEXICO Experiment Controlled conditions PIV measure. 1.3D downstream Open wind tunnel – tunnel effects?

6 Risø DTU, Technical University of Denmark Outline: 1.Background 2.MEXICO Experiment 3.CFD Simulations 4.Conclusion 17 March 09Title of the presentation6

7 Risø DTU, Technical University of Denmark MEXICO Exp. 1/4 MEXICO Info: (pictures by ECN, NLR) Model Experiments in Controlled Conditions Purpose: ”measurements on wind turbine model including the near wake” Large tunnel of DNW used Many groups participated: ECN was coordinator The Vindtunnel: Open section 9.5×9.5m Max. air speed 30 m/s Balance (3 forces/moments) 17 March 09CFD Simulation of the MEXICO Rotor Wake7

8 Risø DTU, Technical University of Denmark MEXICO Exp. 2/4 The Rotor: 4.5m diameter 3 airfoils for each blade: 1. Root: DU 91-W2-250 2. Mid: RISØ A1-21 3. Tip: NACA 63-418 Zig-zag tape at 5% chord Pitch angle -2.3 degrees No signal from strain gages? (global rotor forces are estimated from the balance) Pressure at 5 sections (25%,35%,60%,82%,95%) 17 March 09CFD Simulation of the MEXICO Rotor Wake8

9 Risø DTU, Technical University of Denmark MEXICO Exp. 3/4 The PIV measurements: PIV measuring sheet (34×40cm) placed horizontally at 270 deg azimuth In phase with rotor (freq=3 rotor revolutions) for 40s (100 samples) Axial traverse at r/R=0.82 Radial traverses from r/R=0.5-0.9 17 March 09CFD Simulation of the MEXICO Rotor Wake9 1.3D-1.0D -0.6D-0.4D0.3D1.0D 1/10 scale of DNW wind tunnel Clear tunnel effects in the far wake Tunnel effects limited at the rotor Doeke Rozendal Flow field measurements on a small scale wind turbine model in the DNW PLST wind tunnel NLR-CR-2003-485 Niels N. Sørensen, Risø/DTU MEXICO, 3. Progress Meeting, Athens 28-29 Nov. 2001 Earlier CFD findings

10 Risø DTU, Technical University of Denmark MEXICO Exp. 4/4 Selected data: 100 GB of data Axi-symmetric cond. No yaw Pitch angle -2.3 degree 425 rpm (tip speed 100m/s) Wind speed: 10, 15, 24 m/s (tip speed ratio 10, 6.7, 4.2) 17 March 09CFD Simulation of the MEXICO Rotor Wake10

11 Risø DTU, Technical University of Denmark Outline: 1.Background 2.MEXICO Experiment 3.CFD Simulations 4.Conclusion 17 March 09CFD Simulation of the MEXICO Rotor Wake11

12 Risø DTU, Technical University of Denmark The Simulations 1/5 CFD solver: EllipSys3D RANS: SST k-ω model Fully turbulent Steady-state simulations Surface mesh: All 3 blades meshed 256×64 cells on each Volume mesh: 256 cells in normal direction (~7 rotor diameters) Wake resolved approx 3D Wind tunnel is not included 17 March 09CFD Simulation of the MEXICO Rotor Wake12

13 Risø DTU, Technical University of Denmark The Simulations 2/5 Rotor forces: Thrust. Estimated tower drag subtracted from balance force Pressure distributions. 17 March 09CFD Simulation of the MEXICO Rotor Wake13

14 Risø DTU, Technical University of Denmark The Simulations 3/5 17 March 09CFD Simulation of the MEXICO Rotor Wake14

15 Risø DTU, Technical University of Denmark The Simulations 4/5 Wake results: 17 March 09CFD Simulation of the MEXICO Rotor Wake15 1.3D-1.0D -0.6D-0.4D0.3D1.0D

16 Risø DTU, Technical University of Denmark The Simulations 5/5 Validation dataset : 1.Tunnel effects removed 2.Expands further downstream 3.Airfoil characteristics has been extracted which includes 3D effects 17 March 09CFD Simulation of the MEXICO Rotor Wake16

17 Risø DTU, Technical University of Denmark Outline: 1.Background 2.MEXICO Experiment 3.CFD Simulations 4.Conclusions 17 March 09CFD Simulation of the MEXICO Rotor Wake17

18 Risø DTU, Technical University of Denmark Wake data extracted from MEXICO database CFD simulations of MEXICO wake were performed Measurements and simulations compare well Only the near-wake was simulated (~3D) (due to mesh topology) Simulations with laminar–turbulent transition could be interesting A new validation dataset for wake models without tunnel effects Thank you for listening! 17 March 09CFD Simulation of the MEXICO Rotor Wake18 Conclusions


Download ppt "CFD Simulation: MEXICO Rotor Wake EWEC: 2009 Andreas Bechmann & Niels Sørensen Risø DTU ∙ National Laboratory for Sustainable Energy"

Similar presentations


Ads by Google