Cannot update geometry via design points

thospethospe Member Posts: 1
edited March 29 in 3D Design

Hello,

I believe I have a similar issue to this thread here, though it's not clear if the recommendations there apply to my case. https://forum.ansys.com/discussion/16298/geometry-dont-change-by-solving-different-design-points?

I'm attempting to perform a parameter sweep, modifying the dimensions of a pipe with multiple material layers. I am doing this using driving dimensions in Spaceclaim (see attached image).

I set all of my dimensions row by row in the parameter set dialog. If I set every row to "retain" for every case, then "set current", open up the fluent mesher, manually re-import the geometry and remesh, open fluent, and recalculate, everything works fine. However, if I click "update all design points", or if I just "set current" and update from the workbench, it keeps the geometry of the first design point and I get this error message:

Parameter update incorrect: Attempted = 5.1, Assigned = 4.6, Name = tss1

This only happens with parameters related to the geometry (fluid inlet temperature does not cause this problem). For even a modest parameter sweep, this will take weeks what should be doable overnight, so this workaround is really impractical. Is this a limitation of the student license or am I doing something wrong? Is there a way to force it to re-import the geometry and remesh as part of the run?


Best,

Spencer

Answers

  • kkanadekkanade Posts: 3,298Forum Coordinator

    Can you please upload some more images about which parameters you have defined.

    Please check if each body moved to a new separate component.

    Regards,

    Keyur

    How to access Ansys Online Help Document

    How to show full resolution image

    Guidelines on the Student Community

    How to use Google to search within Ansys Student Community

  • thospethospe Posts: 2Member

    In the attached images, I have one variable, "tside", shown for two different cases (Figs. 1 and 2), as well as "ttop" (Fig. 3) and "tss" (Figs. 4 and 5). There is an additional set of variables that are adjusted together with tss in such a way that the geometry remains properly continuous and the red region has a constant thickness of 0.2 mm.

    Each of these is associated with a pull command. I have a fluid flowing through the center (green) in the y-direction (into the screen) and a heat flux on the surface in the positive z-direction (left). In particular, I am interested in the maximum temperature of the red region.

    If I take two design points, changing tside from 0 to 1 mm (comparing the cases from Figs. 1 and 2), highlight them both, right-click, and "update selected design points", I get 827.364 K in both cases (other output variables report exactly the same results as well). If I manually reload the mesh and run directly in fluent, I get 827.36 K and 817.59 K, respectively.

    On further review, it seems that my issue is nearly identical to this one here: https://forum.ansys.com/discussion/7134/doe-parametric-optimization-solution-is-different-than-fluent-stand-alone

    Like both Flow and Antoinel, I am getting very different results when using the design point interface vs. opening fluent and running from there. Flow claimed the problem went away with the R12020 version, but that is what I'm using. I don't think automatic case modification can help me, as the variables that are causing problems aren't really internal to Fluent, but instead should modify the geometry that is sent to the fluent mesher.

    There doesn't seem to be an obvious pattern to this - sometimes it correctly updates the geometry, sometimes it does not. This can happen with any of my geometric variables; tside and ttop do not give me the error message, I suspect because if one of the radial pull variables (like tss) fails it can result in overlapping geometry or a gap.

    Here are five cases (the arrow corresponds to the boldened variable):

    ttop=0, tside =0, tss=4.6 mm

    ttop=0, tside=1 mm,tss-4.6 mm


    ttop=0, tside=0, tss=4.6 mm

    ttop=0, tside=0, tss=4.6 mm


    ttop=0, tside=0, tss=5.1 mm


Sign In or Register to comment.