CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   -   Area and mass average values on a section (https://www.cfd-online.com/Forums/cd-adapco/55816-area-mass-average-values-section.html)

 Peter N January 24, 2007 15:53

Area and mass average values on a section

Hi,

No-one else seems to be able to help me and it seems that some of the people on this forum know more than anyone else about star.

Here goes;

I am doing an analysis on a mixed flow turbine using Star CD 3.24. I have done a single vane steady state analysis and would now like to evaluate the mass flow averaged temperature at the inlet and outlet to the turbine wheel (not the mesh inlet and outlets) and the area averaged pressures at the same places.

I do have .usr files containing the inlet and outlet coordinates and vertex (or possibly cell) numbers but cannot find a way of using these.

I hope that description of my problem makes sense.

If someone could help me with this I would be eternally thankful

Thanks

Pete

 julien caradonna January 24, 2007 17:59

Re: Area and mass average values on a section

If you want to evaluate an averaged scalar for a cell set: Select the cell set and a coordinate system with the z-axis normal to the section (20) and write:

*set sref 20 load .pst psys sref oper getc volu 1 oper getc sw 2 oper getc T 3 rela or oper getc Ptot 3 oper mult 1 2 5 oper mult 3 5 6 summa cset *get svu rtot 5 *get svup rtot 6 *set pt2 svup / svu

 Peter N February 4, 2007 07:32

Re: Area and mass average values on a section

Thanks Julien, I was intending to do it a little differently at the beginning (i.e. averaging on a plane) but your way may just be the best way about it.

Thanks again

 Balduin Bankerotti February 4, 2007 08:12

Re: Area and mass average values on a section

Something like this might do the job to calculate the mass flow averaged total pressure in a section defined by spoi and snorm:

getc all ptot
oper,getc,dens,5
oper,mult,4,5,6
oper swap 4 6
inte cset
*get, ZAEHLER, tavs
oper swap 4 5
*get, NENNER, tavs
*set, ptot, ZAEHLER / NENNER

 All times are GMT -4. The time now is 20:19.