Hi, I want to use the surface normal vector at curvelinear surface. That is, the normal direction is a variable over the whole surface. Many users in this forum mentioned the CEL variable e.g. "Normal X". But it seems it is not a recognised variable in CFX Pre. Can somebody tell me why? Or give me some hints how to obtain the surface normal. Thanks a lot!

have u try projection vectors on cfx post? do u want to put surface normal vector as BC in PRE? or do u just want to obtain values on post?

Thanks Alex. I want to set the BC in Pre using the surface normal vector. I read some old posts in this forum, one mentioned that the "Normal X" variable e.g., is only valid in Post. I tried to obtain the surface normal vector with User Fortran subroutine USER_GET_MESHDATA, but I failed with setting a correct LOCALE. The comment on this subroutine is not sufficient. I tried to read the LOCALE with the subroutine USER_CALC_INFO. However, the returned LOCALE by this routine can't satisfy the argument of USER_GET_MESHDATA with I try to use it on a wall boundary. Do you have any idea on that?

[Pled]

look at -> Normal vector variable of curved surface