Background
Methods
Mathematical formulation
Corrections for BEM method
Tip and hub losses
Glauert and Buhl empirical corrections
Skewed wake correction
Rotational effect
Verification of the extended BEM model
Application of BEM on 3.5-kW HAWT
Aerodynamic data
Results and discussion
Level | Count |
C
L
|
C
D
| CL R. E. (%) | CD R. E. (%) | y+ max |
---|---|---|---|---|---|---|
Fine | 204,786 | 0.717 | 0.0621 | 0 | 0 | 0.768 |
Baseline | 67,446 | 0.721 | 0.0620 | 0.56 | 0.16 | 1.534 |
Coarse | 33,208 | 0.722 | 0.0623 | 0.70 | 0.32 | 5.332 |
Very coarse | 19,294 | 0.734 | 0.0619 | 2.33 | 0.32 | 5.526 |
Figure number | Operation condition |
---|---|
13 | Fixed rotation speed 12 rad/s, no twisting of the blades, different pitch angles |
14 | Fixed rotation speed 12 rad/s, blade twisted 10 degrees at the root and decrease to 0 degrees at the tip, fixed 7-degree pitch angle |
15 | Fixed wind speed 5 m/s, blade twisted 10 degrees at the root and decrease to 0 degrees at the tip, fixed 7-degree pitch angle |