CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

shock tube reflection boundary conditions euler 1d

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

LinkBack Thread Tools Display Modes
Old   May 7, 2010, 05:33
Default shock tube reflection boundary conditions euler 1d
New Member
michele tuttafesta
Join Date: May 2010
Posts: 1
Rep Power: 0
micheletuttafesta is on a distinguished road
I am starting my PhD in CFD and I'm currently trying to implement
a simple 1D euler solver.
I use a straigthforward upwind scheme to avoid spurious oscillations
and it works fine in a free expansion test case.
The problem arise when I try to insert a reflective wall
at the end of the shock tube.
Immediately after the reflection strong oscillations appear
in front of the backward moving wave.
I suspect they are caused by incorrect numerical boudary condition,
in my case i impose zero velocity at the right last cell boundary and
zero pressure gradient at the same cell boundary.
See the attached figure near the critical time of reflection:
the red line is rho*u, green line is the pressure
I would like to know if there are better ways to implement
reflection or if it is normal to see such oscillations.
Thank you in advance.
Attached Files
File Type: pdf shocktube_reflection.pdf (10.1 KB, 49 views)
micheletuttafesta is offline   Reply With Quote

Old   May 8, 2010, 11:01
New Member
Join Date: Apr 2010
Posts: 14
Rep Power: 8
ares is on a distinguished road
I suggest you to read characteristic boundary conitions. Poinsot and Lele, Lodato, Yoo are some auhors. If you do a google research with characteristic boundary conditions entry you may find a lot of papers.
Physically characteristic boundary conditions are more realistic then imposed values or gradients.
You can see the difference if you do some runs with imposed and characteristic boundary conditions.

ares is offline   Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Impinging Jet Boundary Conditions Anindya Main CFD Forum 25 February 27, 2016 13:58
mass flow in is not equal to mass flow out saii CFX 2 September 18, 2009 08:07
Help with 1D Euler boundary conditions Charlie Main CFD Forum 3 March 15, 2006 17:10
Please help with flow around car modelling! Tudor Miron CFX 17 March 19, 2004 20:23
Boundary Conditions for Euler Kevin Main CFD Forum 5 March 7, 2001 08:15

All times are GMT -4. The time now is 10:48.