I am currently working at NIOSH in Morgantown, West Virginia. We are currently interested in the computational fluid dynamics through an orifice such as a nozzle. We are interested in a time dependent situation in which the nozzle is being turned on and off. If anyone has any information that will be useful to us that woud be wonderful. Thanks.

Can you tell us what information would be useful to you. Simulating trasient flow though a nozzle or a valve is not a problem. With CFD-ACE+ from CFD Research Corporation we and our customers have simulated transient flows through mechanical valves. Some such problems have also included simulation of compliant surfaces which is handled by couple fluid-structure interaction capability of CFD-ACE+.

To learn more about CFD-ACE+, please visit our home on the web at http://www.cfdrc.com. Email me (<a href "mailto:rmm@cfdrc.com">rmm@cfdrc.com</a>)directly for further details.

Dear Amy,

Calculating flows through nozzle on and off seems to be similar to diesel engine fuel flow simulation problems. There is a software called Kiva for hydrodynamic simulations. University of Wisconsin's Engine Research Center is developing this software.

This really does not have anything to do with cfd, but our branch at NIOSH is also interested in obtaining samples of Arizona road dust. We are having extreme difficulty finding some place where we can purchase some samples, so if anyone has any information at all, that would be wonderful. Thanks.

(1). Any 2-D axisymmetric, transient, compressible , viscous flow code should be able to handle it. (2). For small orifice or nozzle, laminar flow should be adequate. (3). To turn it on and off, you control the upstream total pressure conditions.

Amy,

Maybe you could attack an Arizona road with a spade and a bucket? That would give you lots of dust.

Sorry about that. I couldn't resist.....

Glenn

(1). Contact national laboratories first, such as NASA, DOE lab., Air Force Labs. (2). You might be able to find something for free, I mean, a 2-D axisymmetric, transient, compressible, viscous nozzle flow code.

Does anyone know if there is a compressible, axisymmetric, transient, viscous code that will also allow particle injections?

By particle injection, do you mean solving the equations of the flow and the equations of particles in the flow (drag forces, etc..) ? A two-phase flow? Is that for the Nozzle problem above (posted by Amy)?

Patrick

What my boss is wanting is just some information on how the the sample behaves when flowing through the nozzle during a time dependent situation. Does that help? (reply for Patrick)

SOrry, this does not seem to help. By 'sample' do you just mean the flow of the gas through the nozzle, or some particles that you are adding to the gas as tracers to follow the time dependent behaviour of the flow?

For the time dependent Nozzle simulation I guess you can make use of the software proposed by Raza. You can also get a free software from the academy, that does simulate 2D and 3D jets, i.e. after the matter has left the nozzle. The person to contact is Mike (Michael) Norman, at the National Center for Supercomputing Application, at the University of Illinois in Urbana Champaign. The code is called ZEUS (2D or 3D) and the email of Mike is:

norman@ncsa.uiuc.edu

Now if you wish to add particles (tracers to the gas flow) then that's another story. You will have to add some equations to the software and get some references to previous work to do that.

THere has been a tremendous amount of work on Nozzles for all the rocket business (Boeing, Martin-Lockheed, ...), so all the info should be available somewhere. Time-dependent behaviour of nozzels on and off is done on every satelite and Space Shuttle, since this is used for guidance, position, orientation of the spacecraft. So all those involved in that (NASA and others) must have the right reference to it.

Get a look at the web page of the Los Alamos National Laboratory. Check the site

xxx.lanl.gov , you might find some references there.

Patrick