modeling of a moving 3D magnet!

[AndrewSpotlight]

Hi everyone,

I am modeling a 3D magnet and a solenoid. The magnet is moving at a speed (constant or not), and it is moving towards to the solenoid, which is static (fixed to the ground). I want to model the emf and induced current on the solenoid, due to the change of magnetic flux density coming from the magnet.

So far, I have written ANSYS program, but keep getting warning like "Real constant set 1 undefined but referenced by element 1..", I have searched as many ways as I can to fix this error, but couldn't solved the problem at all.

Can anybody give me some suggestion please? Thanks so much!!!!

!**************************************************************
/TITLE,3D single magnet static analysis
/PREP7
EMUNITS,MKS


!************* DIMENSIONS ******************
pi = 3.1415
mx = 0.01
my = 0.01
mz = 0.01 ! dimensions of magnet

cr1 = 0.02
cr2 = 0.019
ch = 0.02 ! dimensions of coil

d = 0.01 ! distance between coil and magnet
l = 0.02 ! air gap

ax = cr2+l
ay = cr2+l
az = 2*mz+d+ch+l ! dimensions of air
care =0.0005*0.0005 ! cross section of coil
n =50 ! turns of coil
cv = pi*(cr2-cr1)*ch ! volume of coil
rcoil = 0.1 ! resistance of coil

d_dmn=0.025 ! depth of surrounding domain
R = 100 ! resistor connected to coil

frqncy=100

xveloc=0
yveloc=0
zveloc=-0.5 ! velocity


!************ GEOMETRIES *****************
vsel,none
block,-mx,mx,-my,my,-mz,mz ! magnet volume
vatt,1,,1 ! assign magnet with mat#1 and typ#1

vsel,none
cylind,cr1,cr2,mz+d,mz+d+ch ! coil
vatt,2,,2 ! assign magnet with mat#2 and typ#2

allsel
cm,magcoi_v,volu
vsel,none
block,-ax,ax,-ay,ay,-az,az
cm,space_v,volu

cmse,all
vsbv,space_v,magcoi_v,,dele,keep ! air volume (space minus magcoi)
cmse,u,magcoi_v
vatt,3,,3 ! assign air with mat#3 and typ#3

alls
vplo


!************* ELEMENTS & MATERIALS *******************
et,1,solid97 ! air (ele #1)
keyopt,1,1,0 ! AZ dof
keyopt,1,2,0 ! no velocity effects
mp,murx,1,1 ! air (mat #1)

et,2,solid97 ! magnet (ele #2)
keyopt,1,1,1 ! AZ dof, volt dof
keyopt,1,2,1 ! velocity effects
mp,murx,2,1.09 ! magnet (mat #2)
mp,MGzz,2,8*1e5
r,2,,,,,,,
rmore,,,xveloc,yveloc,zveloc

et,3,solid97 ! coil (ele #3)
keyopt,2,1,3 ! AZ dof, curr dof, emf dof
keyopt,2,2,0 ! no velocity effects
mp,murx,3,1 ! coil (mat #2)
mp,rsvx,3,8E-9
r,3,care,n,cv,0,0,0
rmore,,0.95


!************ MESH *****************
allsel
smrtsize,10
mshkey,0
mshape,1,3d
vmesh,all


!************ BOUNDARY CONDITIONS *****************
nsel,s,ext ! flux parallel exterior
d,all,az,0


!*********** Solution ************************
/solu
antype,trans
outres,all,all,
time,1
autots,1
deltim,0.01,0.01,0.04
cnvtol,volt
solve
fini

 

[electricpete]

since your question is about your Ansys error message, I would suggest the Ansys forum or the magnetic forum

=====================================
(2B)+(2B)' ?

 

[AndrewSpotlight]

Hi electricpete,

Thanks for your suggestion.

I finally figure this problem out by myself.

=)

Andrew

 

[DimiZ]

Hi andrew,

I am just facing the same problem. I keep receiving the same error as your without managing to solve it.

How did you solve it?

Thank you in advance,

DimiZ

 

[AndrewSpotlight]

Hi DimiZ,

I solved the issue by comparing GUI method with command method, try checking your "real constants" settings in GUI, find out the undefined real constant and define it. For your command method, you need to always add "r,1" for your material 1, same as "r,N" for your material N.

Hope you make it.

Regards,
Andrew