Hello.

I want to analyze rotordynamics with fluid bearings. I have a working APDL script, however I would like to perform the same analysis using Workbench. My problem is as follows:

Since my bearing characteristics are both speed-dependent and length-dependent, I must discretize the whole bearing with 51 bearing elements. While this works neatly in APDL, creating named sections and manually entering all the coefficients is a rather long process.

Is there a way to implement the APDL commands in Workbench?

In /prep7 I define the nodes for the bearings. In /solu I use a loop to import the bearing coefficents corresponding to the respective rotational velocity. So, I think I have to actually insert two APDL command blocks.

I have tried to insert a command block right after I define my connections and insert the commands to create the bearing nodes:

L1 = 7.5e-3

L2 = 18e-3 + L1

ET,2,COMBI214,,0,1 !Unsymmetric bearing in XY-Plane

bearing_opt = 3

TYPE,2

numstr,elem,100001

*if,bearing_opt,eq,3,then

*do,i,1,n,1

n,100000+i,0,5e-3,L1+((L2-L1)/(n-1))*(i-1)!nodes for the bearing stator

REAL,i!assigning real constants

e,node(0,0,L1+((L2-L1)/(n-1))*(i-1)),100000+i!assigning bearing elements over 2 nodes each

*enddo

*endif

In the solution command block I must get the current rotational velocity and then import the corresponding bearing coefficients. The bearing coefficient files are labeled by the rotational velocity in rounds per second. So a rotational velocity of 600 rpm (10 Hz) is labeled as “ansys_bearing_manual_10.

! Get current rotational velocity in rpm, devide by 60 to get rotational frequency

bearing_opt = 3

*if,bearing_opt,eq,3,then

/input,'ansys_bearing_manual_%current rotational velocity in Hz%','inp','P:\Simulation (aktuell)\ansys\Magnet\ansys_bearings_rillen',2,0

cmomega,Rotor,,,f(j)*2*pi

*endif

1.) I am not sure if my approach is correct and possible.

2.) I do not know how to get the rotational velocity.

I am grateful for help of any sort (code, command, example,&hellip. I have attached the APDL Input script, the bearing coefficient files and a dummy Workbench project to implement the commands. If you need further information, please tell me.

Thanks in advance and best regards