[aja1345]

Hi dear friends,

I have simulated a turbine.

This turbine have 8 blades((360/8)=45 deg=angle between blades). Due to the circumferential symmetry, only one eight of the annulus has been computed, imposing periodic boundary conditions in the tangential direction. In my model, the computational domain has been restricted in the axial direction to four chord lengths upstream and eight chord lengths downstream of the blade.

The turbine is as follow:








A complete image of turbine as follow:





The turbine performance is expressed in terms of three non-dimensional coefficients as follow:




The problem is with the value of three above parameter. My solution converges well.
I tried different mesh topologies and all give me almost the same numbers and I used different turbulence model But the value of efficiency is very high compared to experiments. It is greater than 1 while it should be less than 1. Value of total pressure drop is validated with experiments and also value of torque corfficient is near to experiments.

Is there any adjustment that must be made in fluent before starting the calculations? can someone please give us detailed instructions about calculations of these three parameter?

Thanks,

Best,

Aja

[aja1345]

Dear friends ,

I think that the problem is with volume flow rate(m^3/s).

Because the torque coefficient is a bit lower than to experiment and pressure drop coefficient is validated with experiment. therefore, delta p0 is ok.

I can conclude that torque should increase and also volume flow rate should increase until efficiency and torque coefficient are validated.

Now, here I have the question about boundary conditions:

Is there any adjustment that must be made in periodic condition before starting the calculations? periodic c


I selected specify pressure gradient. Is it correct?

I am grateful that guide me about this cases.

Thanks,

Best,

Aja

[aja1345]

Can no-one guide?