[jb pouillard]

HI everyCFD bodies ,

It's the first time I'm simulate pump performance with CFX, I'm fluent user's from the beginning of my works.

I'm simulating pump with volute, modelizing pump with vista CFD bladegen and mesh with turbogrid.

CFX Pre is ok and geen in workbench, but when I'm starting the run, It's does works and I dont understand why.

I try mesh with turbogrid and meshing but it's the same the run doesnt start.

Somebody it's able to help me to lunch the computation ?

the error is the following:
ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| SYMASS_ZIFCS_EL : The solver ran out of temporary space while bui- |
| lding a linked list for a domain interface. Try setting the expe- |
| rt parameter "topology estimate factor zif" to a value greater th- |
| an 1.0. Values higher than 1.2 should not be necessary. |
|

thanks so much in advance

[Overdue]

Hello,

try this:

In CFX-Pre, do a right click on "Solver" > Insert > Expert Parameters > Convergence Control > Memory Control > change the Values for topology estimate factor and +zif to 1.2 (see picture)

[jb pouillard]

Thanks you very much overdue , I find it alone too.
Have you some experience with centrifugal pump analysis ?
Can you give me additionnal informations as:

what is the best way for inlet and outlet bondary condition?
- mass flow at inlet static pressure at outlet
- Pressure at inlet and mass flow at outlet
ok for mass flow but wich pressure I have to use with water ?

Thanks you very much for all

[Overdue]

no sorry, I have no experience with that. Good luck!

[Jiricbeng]

Originally Posted by jb pouillard

Thanks you very much overdue , I find it alone too.
Have you some experience with centrifugal pump analysis ?
Can you give me additionnal informations as:

what is the best way for inlet and outlet bondary condition?
- mass flow at inlet static pressure at outlet
- Pressure at inlet and mass flow at outlet
ok for mass flow but wich pressure I have to use with water ?

Thanks you very much for all

Because you perform simulation with water, I would recommend you to apply mass flow inlet and static pressure outlet. I assume you will run the calculation as single phase and isothermal (and incompressible), in that case it does not matter which pressure you apply at the outlet, if it will be expected pressure given by pump or if you set 0 Pa. The pressure difference between inlet and outlet will be the same in this case. Use reference pressure as 1atm.

[jb pouillard]

Dear Jiricbeng, thank you so much for your advise that I will take in consideration.

If somebody have some experience with NPSHr calculation I'm interresting.

NPSHr = pressure total at inlet - min value of pressure at blades, it's true ?

thank in advance

[turbo]

Originally Posted by jb pouillard

Dear Jiricbeng, thank you so much for your advise that I will take in consideration.

If somebody have some experience with NPSHr calculation I'm interresting.

NPSHr = pressure total at inlet - min value of pressure at blades, it's true ?

thank in advance

No, it is not. Try to read pump basics books.

[jb pouillard]

Thanks you so much turbo for your answer,

Maybe this expression is better:

NPSHr = (pressure at inlet - min value of pressure at blades)/(1000 * 9.81)

[turbo]

No, it is not either. NPSH should consider your liquid vapor pressure at your operating conditions. Try reading books.

[jb pouillard]

Dear turbo,

I'm reading several pump handbook and I can find several expression for NPSH(r).
I can't link it with CFX expression.

I really need help from a pump expert because today I realize that I will not find it alone.

of course I have to compare the minimum static pressure at blade with the vaporization pressure of water....

Please help me

[pawangajare22]

Hey jp can i have ur email id? actually I m also working on the same I have some questions

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