Dynamic meshing 2 stroke engine issue

Click For Summary

Discussion Overview

The discussion centers around the challenges of implementing dynamic meshing in the simulation of a two-stroke opposed piston engine, specifically focusing on the scavenging process and the creation of a user-defined function (UDF) for this purpose.

Discussion Character

  • Technical explanation
  • Homework-related
  • Debate/contested

Main Points Raised

  • One participant seeks assistance with creating a UDF for dynamic meshing in their final project on a two-stroke engine.
  • Another participant questions which part of the mesh needs to move and suggests using a time-dependent boundary condition instead.
  • A participant clarifies that a UDF is necessary for dynamic meshes and specifies the need to move two piston heads in opposite directions within the same cylinder.
  • One participant mentions their unfamiliarity with UDFs, indicating they use CFX for simulations.
  • A different participant expresses a similar need for programming a UDF for dynamic meshing in their own simulation of a two-stroke opposed piston engine.

Areas of Agreement / Disagreement

The discussion reflects a lack of consensus on the best approach to implement dynamic meshing, with multiple participants raising questions and seeking clarification without reaching a definitive solution.

Contextual Notes

Some assumptions about the requirements for dynamic meshing and the specifics of UDF implementation remain unclear, and there are unresolved technical details regarding the mesh movement and boundary conditions.

tonisantos
Messages
3
Reaction score
0
Hello everyone,
im a 5th year student and I am doing my final project which consists on analyzing the scavenging process of a 2 stroke opposed piston engine, but I am having a hard time creating the UDF for the dynamic meshing thing.
Could anyone please help me?
 
Engineering news on Phys.org
OK, first, what part of the mesh needs to move? Why do you not just apply a time-dependent boundary condition?

Also, what is a UDF file? I assume something related to the grid motion.
 
UDF (user defined function) is required to get dynamic meshes working...
I need to move 2 piston heads inside the same cilinder in oposite directions
 
Right, we use CFX here, so I'm not familiar with these UDFs.
 
Hello, I am also simulating a two stroke opposed piston engine. Has anyone managed to program a UDF for the dynamic mesh please? Thanks.

Darren
 

Similar threads

  • · Replies 123 ·
5
Replies
123
Views
33K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
13K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
4
Views
6K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
4
Views
3K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 11 ·
Replies
11
Views
12K