Changing the surface roughness

Changing the surface roughness may be required if the default surface finish is not true of your case.  For example, a stainless steel finish may have a surface finish near 0.0005 inches or a cast volute may have a surface roughness near 0.001 inches.  It is best to talk with your manufacturer before changing the value arbitrarily.

The default surface roughness used by Code WAND is 0.0001 inches which represents a hydraulic smooth finish.  Though there is no way of changing the surface roughness used by Code WAND, you are able to change the surface roughness value for a restart file using Code LEO.

To do this, a user can use IRUN option 4 in the .LEO setup files as below.  Replace with the desired amount

*RESTART-FILE-NAME
 stator0.REST
*NITER, MPID, PRUN, IPRT,NIRST, IPLT
  1000   101     1    20   100     1
*ITURB,ITIME,EMODE,IFAST,IGAMM, IRUN
     1     0     0     1     1     4

In a situation where multiple IRUN options are required.  It is recommended that you run IRUN option 4 for 0 iterations to get a new restart file with the updated surface roughness value.

You can check the surface roughness value by running ads-gleo.  Please note that the value shown in the output is in inches.

ads-gleo .REST toc

The surface roughness can be found here:

CARD 2:  
  RPMS    :  0.1037899     RPM                            
  PGAUG   :  1.497035     GAUGE PRESSURE     16.8924     SLUGS/FT**3
  EGAUG   :  3.749813     GAUGE ENERGY                   
  FVS     :  1.000000     FRICTION INDICATOR             
  SFRL    : 9.9999997E-05 SURFACE ROUGHNESS                
  TWAL    :  0.000000     WALL TEMPERATURE                
  PNLL    : 0.7000000     PRANDTL NUMBER                 
  PNTL    : 0.9000000     TURBULENT PRANDTL NUMBER        
  TFREE   : 9.9999998E-03 FREE STREAM TURBULENT LEVEL      
  LFREE   : 9.9999998E-03 FREE STREAM LENGTH LEVEL       
  BLK    NI    NJ    NK    F1    F2    F3    F4    F5    F6
    1   109    13    49     5     6     0    14     9    11
    2   109    13    49     5     6    13     0     9    11
    3   161    21    49     0     0    10     0     9    11
    4    21    13    49     5     0     0     0     9    11
    5    21    13    49     0     6     0     0     9    11
    6   161    13    13     0     0     0     0    10    11
NUMBER OF GRID POINT IN THIS SECTOR  358498

 



Code
LEO
Author
Michael Ni
Date Created
2017-03-21 01:34:21
Date Updated
2017-03-21 06:05:52
Views
1920