|
[Sponsors] |
October 13, 2023, 05:45 |
Problems with non-reflective outlet/opening
|
#1 |
New Member
Paul
Join Date: Oct 2023
Location: Germany
Posts: 1
Rep Power: 0 |
Hey,
I'm facing some issues with the non-reflective boundary condition at an outlet/opening, I tried both. I'm running a simulation to get the pressure fluctuations at an outlet. It is a transient analysis with a moving mesh to compute a compression. At a given moment in time there is another mesh motion which closes an interface to get the flow out of the compression domain into a collector duct. To figure out the pressure fluctuations at the outlet of the collector duct, I need a non-reflective boundary there. At the outflow area I set the pressure boundary. When using a non-reflective opening I won't get fluctuations around the target opening pressure of 130 bar. The average over time is at 128 bar. It never reaches the set pressure. Is there anything I can do to nail the set value in average, with the non-reflective opening boundary? Because it couldn't reach the defined pressure, I switched to non-reflective outlet boundary. Which worked, but with a partial wall which has been placed there during the run. This didn't make sense to me, because there shouldn't be any backflow. Now I enlarged the collector duct, same element sizes, just a few more and same timestep, but this doesn't work at all with non-reflective outlet. I can't find any problematic areas in the domain, just at the boundary. After a view timesteps there is a wall at portions without any recirculation downstream or at the outlet, but I can see escalating velocities and get a fatal overflow. Can anybody give me a hint what might be the problem there? Thanks in advance, Paul |
|
Tags |
non-reflective |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
[ICEM] Problems with coedge curves and surfaces | tommymoose | ANSYS Meshing & Geometry | 6 | December 1, 2020 11:12 |
Reflective wall and non slip condition? | Jaydi_21 | Main CFD Forum | 6 | February 20, 2018 14:43 |
[mesh manipulation] Problems with rotational cyclic boundaries | TReviol | OpenFOAM Meshing & Mesh Conversion | 8 | July 11, 2014 03:45 |
[ICEM] Flow channel meshing problems | StefanG | ANSYS Meshing & Geometry | 19 | May 15, 2012 06:44 |
Help required to solve Hydraulic related problems | aero | CFX | 0 | October 30, 2006 11:00 |