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

fluent internal nozzle flow

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

Reply
 
LinkBack Thread Tools Display Modes
Old   December 4, 2012, 04:38
Default fluent internal nozzle flow
  #1
New Member
 
matt
Join Date: Oct 2012
Posts: 8
Rep Power: 4
sharkforce is on a distinguished road
Hello, I need help setting up the physics for this problem in fluent.

I have a 15 degree conic nozzle which I have created the geometry, and meshed (see attached) and named edges for the inlet and outlet.

Total Pressure = 2.5 MPa
Total Temperature = 2500K
exit mach should be 3.0

here is what I used:

Physics-setup

General
Density-Based Solver : selected because was originally designed for high-speed compressible flows.
Time: Steady
2D Space: Planar

Models
energy equation: on energy equation is coupled to the continuity and momentum equations
Viscous model: inviscid

Materials
Air - Set density to ideal gas

Cell Zone Conditions
Surface_Body Operating pressure set to 0 Pa

Boundary Conditions
inlet: type pressure-inlet, Gauge total pressure:2500000 Pascal, Gauge Total Temperature 2500 K constant
outlet: type pressure-outlet, Gauge total pressure: 0 Pa, 300K

Solution Methods

Formulation:Implicit ,Flux type: Roe-FDS
Spatial Discretization: Least squares cell based
flow
Second order upwind

So... I ran calculation with solution steering, 1000 iterations, flow type supersonic, use fmg initialization


and well it does not look as I had expected. what should I do instead so that I have mach=1 at the inlet, and so that it expands to mach 3 at the exit. the geometry was determined by method of characteristics to do this with the input data.
geometry.jpg

mesh.jpg

velmag.jpg
sharkforce is offline   Reply With Quote

Old   December 4, 2012, 05:49
Default
  #2
New Member
 
matt
Join Date: Oct 2012
Posts: 8
Rep Power: 4
sharkforce is on a distinguished road
re ran with a modified geometry including a convergent seciton... results look more like they should, but is this necessary? mach.jpg
sharkforce is offline   Reply With Quote

Reply

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
calculate a nozzle flow using rhoCentralFoam hg2lf OpenFOAM 0 October 25, 2012 22:26
What the differences flow equation of Fluent 6.3 and Fluent 12.1 opehterinar81 FLUENT 0 August 19, 2011 12:55
UDF for transient pressure inlet, mass flow check at nozzle exit and volumetric heat kokoory FLUENT 0 August 17, 2011 03:07
analyze a cd nozzle with fluent which designed by MOC mehrzad Main CFD Forum 0 July 6, 2011 05:33
compressible flow in a counterflow nozzle d.vamsidhar FLUENT 0 November 24, 2005 02:45


All times are GMT -4. The time now is 08:37.