CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Exhaust pipe 2T engine pressure waves simulation

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 7, 2017, 15:57
Talking Exhaust pipe 2T engine pressure waves simulation
  #1
New Member
 
Cristian
Join Date: Jun 2017
Posts: 3
Rep Power: 5
sir--kris is on a distinguished road
Hi guys,

I facing to a problem in Fluent Ansys 16:
I wish to symulate the progress of the reflecting pressure waves
into an exhaust system of a 2 strokes engine.
As first step I wanna symulate a very simple axisymmetric 2D duct
made up of a first part with constant section and a second part of a divergent section. The gas can be simple air (in this first step).
Pressure in atm.

The goal would be to can see how the reflecting pressure (low pressure
in this case) waves coming back after the exhaust port opening and
gas emission.

I think I need of a UDF (that I can't write ) simulating the pressure evolution (or maybe the flow velocity, I don't know) on the inlet. I think maybe a spike type function and make a temporal (transient) simulation until the pressure wave come back to the inlet.

I don't know how set up the problem about the inlet BC.
Perhaps I have to set only a pressure simulating a pressure wave at
sonic velocity? Or only a sonic flow (flow velocity)?
Or maybe both?
What kind of solver setting or other thinghs do you suggest?

Please feel you free to ask anything else you need to understand the problem.

I attach here the initial file .cas concerning the problem.

A gif that explanes the phenomena:

https://it.wikipedia.org/wiki/Camera...e_Zweitakt.gif

Kind regards
sir--kris is offline   Reply With Quote

Old   June 8, 2017, 13:29
Default
  #2
New Member
 
Cristian
Join Date: Jun 2017
Posts: 3
Rep Power: 5
sir--kris is on a distinguished road
Sorry guys I has forgotten to attach the cas file.

Regaaaaards
Attached Files
File Type: zip exhaust_simple.zip (157.5 KB, 0 views)
sir--kris is offline   Reply With Quote

Old   June 12, 2017, 06:11
Unhappy
  #3
New Member
 
Cristian
Join Date: Jun 2017
Posts: 3
Rep Power: 5
sir--kris is on a distinguished road
Hi, no one tip?
sir--kris is offline   Reply With Quote

Reply

Tags
exhaust, expantion, pipe, sonic, wave

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
CFX Solver stopped with error when requested for backup during solver running Mfaizan CFX 40 May 13, 2016 06:50
pipe with orifice, pressure drop declines when pipe gets longer (BC problem?) cristopf OpenFOAM Running, Solving & CFD 0 January 21, 2016 04:55
what boundary condition is proper for simulation of shock-tube low pressure part? immortality OpenFOAM Running, Solving & CFD 0 May 2, 2013 13:22
measured pressure in the discharge pipe jumps Jan Main CFD Forum 1 October 30, 2006 07:54
Hydrostatic pressure in 2-phase flow modeling (long) DS & HB Main CFD Forum 0 January 8, 2000 15:00


All times are GMT -4. The time now is 13:33.