Simulation of Helical coil using VOF

- March 6, 2019 at 5:44 am
  
  snr1
  Subscriber
  
  I am trying to create a structured mesh for a helical coil in ICEM CFD. But I was not succeeded. Later I shifted to unstructured mesh generation in a workbench. While doing so, I have created inflation layers with first layer thickness. But inflation is not created and it shows "Hard edges are not supported and may be ignored for pre-inflation, please check your model carefully." How to resolve it? Is it possible to generate a structured mesh for a helical coil in ICEM CFD? if so, can anybody help me?
- March 6, 2019 at 6:07 am
  
  Keyur Kanade
  Ansys Employee
  
  as ansys employees we can not download attachments. can you please insert some zoomed in images of your geometry.
  
  in general, icem can be used for hex mesh in helical geometry.
  
  for your geometry, go to dm, then use tools - repair - hard edges. then go to meshing and create tet mesh with inflation.
  
  if this helps you, please mark this post as 'is solution' to help others on forum.
- March 6, 2019 at 6:22 am
  
  snr1
  Subscriber
  
  DOMAIN
  
  How to generate structured mesh for a helical coil in ICEM CFD? please help me.
  
  AND i tried to repair the hard edges in DM, but it has given following.
- March 6, 2019 at 10:19 am
  
  Rob
  Forum Moderator
  
  If you sweep the body in Workbench (ANSYS) Meshing does it work? That'll give you an unstructured hex mesh, and you can inflate it too. Probably easier than trying to block the body manually in ICEM CFD.
- March 6, 2019 at 10:43 am
  
  snr1
  Subscriber
  
  Tq sir, but for hexa mesh, inflation is not working. I created geometry in SolidWorks and imported into a workbench. Can you suggest any alternative?
- March 6, 2019 at 12:00 pm
  
  Rob
  Forum Moderator
  
  Set the body mesh to sweep and set a manual source. Then inflate the sweep method (right click on the tree entry): sweep inflation is applied to the source face from the edge(s).
- March 6, 2019 at 12:15 pm
  
  snr1
  Subscriber
  
  Tq sir, i will try it and let you know the result. How to control number of layers in this method with required y+ value?
- March 6, 2019 at 1:17 pm
  
  Rob
  Forum Moderator
  
  Same as any inflation method: it's just applied slightly differently.
- March 7, 2019 at 2:39 am
  
  Keyur Kanade
  Ansys Employee
  
  for such geometry, sweep may not work in one go.
  
  you may need to split the geometry in few bodies.
  
  e.g. split 360 degree into 4 bodies of 90 degrees.
  
  then use sweep method.
- March 7, 2019 at 5:42 am
  
  snr1
  Subscriber
  
  What is the best and simple method to generate a mesh for the above helical coil?
- March 7, 2019 at 11:46 am
  
  Rob
  Forum Moderator
  
  I'd sweep it.
- March 7, 2019 at 12:23 pm
  
  snr1
  Subscriber
  
  What is the best and simple method to generate a mesh for the above helical coil?
- March 9, 2019 at 8:21 am
  
  snr1
  Subscriber
  
  Can anybody suggest, What is the best and simple method to generate a mesh for the above helical coil?
- March 11, 2019 at 3:27 am
  
  Keyur Kanade
  Ansys Employee
  
  this is already mentioned by rob and me. you will need to use sweep method.
- March 11, 2019 at 5:12 am
  
  snr1
  Subscriber
  
  Okay tq sir for your reply
- March 11, 2019 at 10:36 am
  
  snr1
  Subscriber
  
  But the problem is inflation option is not working once we sweep the mesh. But i want to make inflation layers to capture the near wall effects. So, how to proceed further?
- March 11, 2019 at 11:11 am
  
  Rob
  Forum Moderator
  
  Inflation for sweep is set slightly differently.
  
  Set up the mesh method for the zone as Sweep and set a manual source face (one end of the coil).
  
  Once the sweep method is set, right click on the sweep method in the tree & inflate this method.
  
  Apply the inflation to the end face & perimeter edge.
  
  You may need to adjust the number of layers & cell size as it's quite a small diameter so inflation may give a poor mesh if you don't get the sizing right. You're also aiming for an aspect ratio of 1-2 up the tube to get the VOF interface correct: you may find the cell count is very high so may need to reduce the length of the coil.
- March 11, 2019 at 11:25 am
  
  snr1
  Subscriber
  
  nice the sweep method is set, right click on the sweep method in the tree & inflate this method. Apply the inflation to the end face & perimeter edge.
  
  I didn't understand this. If your mind can elaborate clearly
  
  thanks for your patience.
- March 11, 2019 at 4:30 pm
  
  Rob
  Forum Moderator
  
  Watch this video from about 4:40 https://www.youtube.com/watch?v=rDvzJ7UsQU8
- March 12, 2019 at 4:19 am
  
  snr1
  Subscriber
  
  Tq sir, i got it
- March 13, 2019 at 5:44 am
  
  Keyur Kanade
  Ansys Employee
  
  if this helped you, can you mark this as 'is solution' to help others on forum.
- March 13, 2019 at 7:00 am
  
  snr1
  Subscriber
  
  Tq sir, I was able to develop good mesh by using sweep method. Greatly appreciated for your help
- March 15, 2019 at 4:34 pm
  
  snr1
  Subscriber
  
  Dear sir, if I run without UDF, it results floating point exception error and temperature limited in 20 cells of zone1. How to resolve these issues?
  
  Actually, I am simulating the water evaporation process in the helical coil. The boundary conditions are
  
  inlet: water (100%) with mass flow rate inlet and temperature (370K)
  
  wall: constant temperature (500K)
  
  outlet: outflow
  
  operating conditions: 101325 Pa and 300K
  
  saturation temperature in the evaporation and condensation model: 373K with 0.1 frequency.
  
  model: VOF implicit with implicit body force
- March 15, 2019 at 4:49 pm
  
  Rob
  Forum Moderator
  
  Let's keep the mesh here & solver stuff here /forum/forums/topic/mpi-error/ so I'll move the last post & lock.