Difference between revisions of "Module Turbine"
From MohidWiki
(→Forces) |
(→Coefficient parameterisation) |
||
| Line 23: | Line 23: | ||
=== Coefficient parameterisation === | === Coefficient parameterisation === | ||
| + | ''C_{T}='' | ||
| + | *''0'' if U≤U_{C} | ||
| + | *''C_{T_0}'' if U_{C}<U≤U_{D} | ||
| + | *''C_{T_0}U_{D}^{3}/U^{3}'' if U>U_{D} | ||
| + | * | ||
| + | * | ||
| + | |||
| + | ''C_{P}='' | ||
| + | *''0'' if U≤U_{C} | ||
| + | *''C_{P_0}'' if U_{C}<U≤U_{D} | ||
| + | *''C_{P_0}U_{D}^{3}/U^{3}'' if U>U_{D} | ||
| + | |||
| + | Where C_{T_0} and C_{P_0} are the design values for each coefficient and U_{C} and U_{D} are the cut-in and design speed, respectively | ||
=== Vertical discretisation === | === Vertical discretisation === | ||
Revision as of 11:46, 16 July 2019
Contents
Overview
Module Turbine is in charge of calculating the force exerted by turbines in the water flow as well as the power and energy extraction. This implementation is available for 2D and 3D simulations being, in the 3D model, only discretised in the vertical domain. There is no discretisation of the turbine geometry (and force) in the horizontal domain, the model computes the force as a punctual force in the cell where the turbine is placed.
For the moment, the model is thought for horizontal bidirectional turbines, with pitch control and free rotation in the vertical axis (the perpendicularity between flow and turbine is implicit in the model as the force is introduced into the hydrodynamic model as a punctual force).
Implementation
Forces
Failed to parse (unknown error): \text{F}_{T} = \frac{1}{2}\rho A_{T} C_{T} U^{2}
Failed to parse (unknown error): \text{P}_{T} = \frac{1}{2}\rho A_{T} C_{P} U^{3}
Thrust force produced by the turbine rotor due to the energy extraction
F_{T} = (1/2)ρA_{T}C_{T}U^{2}
The power extracting by the turbine
P_{T}=(1/2)ρA_{T}C_{P}U^{3}
Where ρ is the water density, A_{T} is the area swept by the blades, C_{T} is the thrust coefficient that quantifies the force exerted by the turbine to the flow and C_{P} is the power coefficient that quantifies the amount of power extracted from the flow.
Coefficient parameterisation
C_{T}=
- 0 if U≤U_{C}
- C_{T_0} if U_{C}<U≤U_{D}
- C_{T_0}U_{D}^{3}/U^{3} if U>U_{D}
C_{P}=
- 0 if U≤U_{C}
- C_{P_0} if U_{C}<U≤U_{D}
- C_{P_0}U_{D}^{3}/U^{3} if U>U_{D}
Where C_{T_0} and C_{P_0} are the design values for each coefficient and U_{C} and U_{D} are the cut-in and design speed, respectively
