How to use cfd to calculate power output of vertical axis wind turbine ?

I have a question on Cp in the wind turbine. I have calculated the moment in the z-axis as my rotor also rotors along the z-axis. I got the moment values from my simulation. I applied the procedure which ansys recommended formula (P= torque x rotational velocity) for extracting power from the turbine. I got huge discrepancies between actual and theoretical. After calculating power, I have calculated Cp it comes around 0.8 to 1, but the Betz limit is 0.59. plz help me to calculate the Cp.

Conditions :

Turbine Aera =17.5 m2

R=3.5m

V=3

omega=2.14 rad/s

TSR=2

Fluid water (990 is the density)

 

Hello Everyone, I am simulating a small wind turbine using Ansys Fluent 19.0. Because of problem periodicity only one third of the fluid domain is simulated. The generated power is calculated using this equation: P=T*omega, with T is the rotor torque. My question is: the torque in this equation, is-it the calculated torque found by Ansys multiplied by 3 or only the calculated value ?.

Thank you.

Hello everyone!

I'm doing a simulation in fluent and at some point, usually after the first 15 steps, the error appears:

Divergence detected in AMG solver: temperature

Divergence detected in AMG solver: temperature

Error at host: floating point exception

Error at Node 0: floating point exception

Error at Node 1: floating point exception

===============Message from the Cortex Process================================

Compute processes interrupted. Processing can be resumed.

==============================================================================

Error: floating point exception

Error Object: #f

I'm compiling a UDF file, Time transient, convergence criterion relative, number of time steps 1000, able Specified Operating Density like zero kg/m^3. The mesh is refined in the best possible way.

What is the reason behind it?

Best regards.

I'm simulating a multi body flow under Ansys Workbench, when meshing i receive a message showing an overlapping contact region which does not lead fluent to capture the turbulence aspect

Hi all, I am trying to calculate the output power of wind turbine and the power should be zero below cut in and above cut out and equal to rated from rated speed till cut out

my question is what about the part from cut in till rated speed , i used the general equation to calculate it which is

p=0.5*swept area* air density*capacity factor *v3

the problem is some values above rated power is there any thing wrong i need help

vertical axis wind turbine is rotating with a known RPM. Practically, how to measure the torque by utilizing the rotating shaft attached to the turbine?

As I start the simulation of bubble column (air-water system), just after 15 iterations, it displays "floating point exception" and shows "divergence detected in AMG solver". What is the reason behind it?

pcm in ansys fluent