Abstract
The lift and drag coefficients of the rotating Savonius wind machine are determined from the pressure difference measured between the upper plane and the lower plane of a blade. Pressure measurements have been performed for two sets of experiments; the first one for U ∞ = 10 m/s and the second one for U ∞ = 12.5 m/s. In each case it is to be noted that a negative lift effect is present for low values of the tip speed ratio λ. The lift coefficient becomes positive when λ increases. The drag coefficient is of course always negative.
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Abbreviations
- A :
-
rectangular area of the wind tunnel
- C x :
-
drag coefficient
- C Y :
-
lift coefficient
- {ovC} x :
-
averaged drag coefficient
- {ovC} Y :
-
averaged lift coefficient
- D :
-
rotor diameter
- h :
-
rotor height
- R + r :
-
radius of rotation of a blade
- Re :
-
(U ∞ · D)/v Reynolds number
- S :
-
rotor projected area
- U ∞ :
-
wind velocity
- δ :
-
central gap
- λ :
-
tip speed ratio
- ν :
-
cinematic viscosity
- ϱ :
-
density of air
References
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Chauvin, A., Benghrib, D. Drag and lift coefficients evolution of a Savonius rotor. Experiments in Fluids 8, 118–120 (1989). https://doi.org/10.1007/BF00203076
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DOI: https://doi.org/10.1007/BF00203076