[aerospace84]

fluid domain around blades and blades should be rotating!

[didane]

Originally Posted by urbanzakapa

I really need your help, when I did mine, VAWT 3blade, all I got for Cm are very small values, all of them, for example, 0.02, so then my Cp would be small too, because Cp=Cm*TSR, so I am now start to wonder whether I have done it wrong since the first step,

Can I get your help over these problem, please, thanks.

Here is my email: qusyairi315@yahoo.com

Dear Qusyairi Amiruddin, Have u solved your problem? i'm encountering similar problem too..Thanks in advance

Kind regards

[FaSe]

Originally Posted by dalecooper

Hello CFD_LES,

Finally I was able to solve my problem of negative Cm values in my simulations. All I did was to restart again with the geometry and meshing. So I think there was some problem with the interfaces between the stationary and rotating domains, but I'm not sure if that was the reason. All I can tell you is that after that I began to obtain positive Cm values.

Nowadays I'm doing some simulations in order to obtain the coefficient of performance of the turbine as a function of the tip speed ratio (TSR). The results look pretty good except, for a unique point (TSR=1.5) where the Cm has an abnormal value. I was expecting to obtain an increasing Cm value up to a certain point where the turbine is most efficient, and after that the Cm should begin to decrease.

I have tried with different inlet velocities, but the behavior is exactly the same, and also the critical point is located at TSR=1.5

Best regards

Hi all,
I am simulating a 2D VAWT with 2 blades in ANSYS Fluent 16. I am validating my results (Cp vs TSR). at the interval 1.2<TSR<2 , i get good results but in the range TSR<1.2 , i get negative values for Cp (Coefficient of Power) and in the range TSR>2 , Cp values increase by increasing TSR which is not correct because Cp should reach to a maximum value for a specific TSR and after that should decrease.

I am doing my thesis and REALLY NEED YOUR HELP.

[Mabrouk]

hello,
How can i do a good mesh for hydro turbine?

[rudipewe]

Dear All,
Would u please help me. I am a newbie in Ansys Fluent. I do the simulation of VAWT with rotation and revolution on the blade. I got the good result on blade Cm, but not on axis (rotor) Cm. Herewith my mesh, and excel result for axis and blades. Thank you very much..
torque revolution.jpg

torque rotation.jpg

Contours of Total Pressure.jpg

[mstrkr]

Hello everyone
I have problem with my project. I have analyzed hydro turbine in pipe. When I m increasing the TSR value I m getting increasing Cp value contuniously. Even Cp is exceed 1. So there is a problem but I dont know what. Please help me...

[satyamshk2]

Area= Diameter of the turbine in 2D
Length= Radius for moments, Depth=1 for 2D
Velocity as a free stream

[satyamshk2]

Area-Diameter of turbine as H is unity
Length= radius of turbine to calculate torque
velocity-inlet freestream