1. D.G. PHILLIPS, P.J. RICHARDS and R.G.J.FLAY
DIFFUSER DEVELOPMENT FOR A DIFFUSER AUGMENTED WIND TURBINE USING COMPUTATIONAL FLUID DYNAMICS
D.G. PHILLIPS, P.J. RICHARDS and R.G.J.FLAY

2. The University of Auckland, New Zealand

3. The Vortec 7 Diffuser Augmented Wind Turbine
Originally designed by Grumman Aerospace in the early 80’s, but built in New Zealand in 1997.

4. New Zealand is a long way from anywhere!
There is very little of anything to slow the wind.

5. Diffuser Augmented Wind Turbines (DAWT)
Conventional Bare Wind Turbine

7. Geometry of the Vortec 7 Diffuser Outlet Flange Secondary Slot
Turbine Blade
Inlet Truss
Structural Inlet Ring
Diffuser Outlet Flange
Inlet Slot
Original Vortec 7
Instep C

9. Geometry of the Vortec 7 Diffuser Outlet Flange Secondary Slot
Turbine Blade
Inlet Truss
Structural Inlet Ring
Diffuser Outlet Flange
Inlet Slot
Original Vortec 7
Instep C

10. Geometry of the Vortec 7 Diffuser Outlet Flange Secondary Slot
Turbine Blade
Inlet Truss
Bullnose
Structural Inlet Ring
Diffuser Outlet Flange
Inlet Slot
Original Vortec 7
Modifications
Instep
Nosecone C

11. Modelling the as-built Vortec 7

12. Modelling the modified Vortec 7

13. Vector Map for the modified Vortec 7

15. Wind Tunnel Modelling

16. CFD modelling of the new diffuser

18. Original comparison

19. Comparison including blockage effects.

22. Latest Design

23. CONCLUSIONS
Computational modelling has proved to be a valuable tool in the development of diffuser designs for a diffuser augmented wind turbine.
The combination of computational modelling, wind tunnel modelling and full-scale testing has made it possible to identify deficiencies in the other techniques.

24. 3rd International Symposium on Computational Wind Engineering
University of Birmingham, England September 2000
COMPETITION
To model the flow around a 6m Cube in a rural atmospheric boundary layer