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## Simulation Mechanical and Multiphysics

Member
Posts: 3
Registered: ‎07-13-2011

# CFD on a object

2228 Views, 5 Replies
07-26-2011 11:49 AM

Hi i was wondering if i could do wind tunnel analysis on an object such as an airplane or a car and collect data on surface pressure and more importently if i could get a value for the coeffcient of drag for said object. The question is if i could get results similar to this : http://www.youtube.com/watch?v=ER8qjvdHEyQ&feature=related﻿

Employee
Posts: 259
Registered: ‎06-14-2010

# Re: CFD on a object

Yes, you can. This is a typical external flow case in fluid flow, which needs modeling an enclosure(usually a box) to include the airplane/car inside, remember to model air part in CFD analysis and leave enough distance to allow the flow stabilized at outlet. A common practice is to have fix velocity at inlet and zero pressure at outlet, which is pretty much like the process as real wind tunnel test.

In Autodesk Multi-physics simulation, you can get the velocity and pressure distribution in the air domain, and the reaction force due to aerodynamic effect, the reaction forces are located on the surface nodes on the airplane, using the summation in post-process to get total lift and drag force, and then one can calculate the lift/drag coefficient at certain attack angle (in airplane case).

Jianhui Xie, Ph.D
Principal Engineer
MFG-Digital Simulation
Member
Posts: 3
Registered: ‎07-13-2011

# Re: CFD on a object

Alright thank you verymuch, and quick question, is there possibly a tutorial on this because im not that familar with simulation software yet as im still a student and it is very overwhelming for me .

Employee
Posts: 259
Registered: ‎06-14-2010

# Re: CFD on a object

It seems to me that there are no direct tutorials for this kind of external flow.

Please have a look of this previous thread " Re: CFD for Air Flow Modeling", On the bottom of this thread, I have uploaded two archived files as examples. They are 2-D models for flow through submarine with certain attack angle.

http://forums.autodesk.com/t5/Autodesk-Simulation/CFD-for-Air-Flow-Modeling/td-p/2674365

And the link to the archive file is here

http://forums.autodesk.com/autodesk/attachments/autodesk/396/1256/1/2300_2Dsubm_10deg_st.zip

Jianhui Xie, Ph.D
Principal Engineer
MFG-Digital Simulation
Employee
Posts: 492
Registered: ‎03-25-2010

# Re: CFD on a object

Please go to "Getting Started > Help > Tutorials". Although the "Ball Valve Fluid Flow Analysis" is an internal flow instead of an external flow, it will at least get you started.

For external fluid flow, please go through this example in the Help documentation: "Getting Started > Help > In-Product Help > Autodesk Simulation > Examples > Fluid Flow > 2D Cylinder with Wake Vortex".

Sincerely,
John Holtz, P.E.
Senior User Experience Designer, Simulation
Autodesk, Inc.

Current version of Mechanical & Multiphysics: 2013 SP1 (2013.01.00.0012 28-Jun-2012)
Contributor
Posts: 19
Registered: ‎12-22-2011

# Re: CFD on a object

02-08-2012 04:27 AM in reply to: INACTIVE_AstroJohn

hi, id like to do an interanl fluid flow, througha  pipe with a turbine blade constrained within, are there any tutorials that can help with this, the ball valve tutorial doesnt have any inners.

thanks

ryan