# geom_decompose: wrong face numbering

2 messages
 I need to model two small wires segments (1 cm) in a large tank on either side of a disk that is about the size of a person: The grid generation gets an error: geom_decompose: wrong face numbering. DiskNtankBetweenwires.feaBy shrinking the 'x' dimension (tank +/- 7.5m, wires at +/- 6m): ....the grid will generate: DiskNtankBetweenwires-gridGenWorks.feaBut if the block (B1) x_min value is set to -7.51 (from -7.5), it fails. I have tried smaller grid sizes.  I tried specifying grid size for each subdomain. What about reorienting the objects? The wire dimensions are very small compared to 10m.  0.5mm radius. So that's a ratio of 10/.0005 = 2e4... Does this ratio (largest dimension to smallest dimension) have a practical limit?  Could some FEATool tolerance be changed by the user that might allow a greater difference (at some processing cost, no doubt).   Unlike some of my models which turn out to be exploratory/learning tools, this one is tied to a specific geometry and experiment hat I want to replicate. Any hints as to how to go about finding the problem and/or how to solve it would greatly appreciated. Kind regards, Randal
 Administrator randress wrote geom_decompose: wrong face numbering.  This message indicates that there has been an error in the decomposition of the geometry into minimal and non-overlapping domains. This should be equivalent to getting the intersection of OBJ1 and OBJ2, and OBJ1-OBJ2, as well as OBJ2-OBJ1 (if you manually create the minimal regions and it might work). I'm guessing the issue is the scale difference that the geometry engine can't handle well, I will try to have a look when I can but I'm not sure there is an easy fix. High aspect ratio/scale differences is unfortunately always very hard for these types of simulations, geometry, grid generation, as well as solvers.