[megacrout]

Hi everyone,

I have to solve different cases of reacting flows (through a pipe) but - being new to OpenFOAM - I do not know what solver(s) I have to use.

Here are the parameters I have as input (several different cases):

- Empty pipe or filled with a porous media (catalyst)
- Adiabatic or isotermal reaction conditions
- All three possible flow types (laminar, intermediate or turbulent)
- Premixed stream
- Scale: dm-range (say, 20cm in diameter and long enough to reach spatial steady-state but this is not critical to me)
- No moving boundaries

- Up to 20 species (reactant, inert, product)
- Up to 10 simultaneous reactions (not only combustions)
- Simple or combined (parallel and/or chain) reactions
- Fast or slow reactions
- Arrhenius or more complicated reaction models (e.g. Langmuir-Hinshelwood)

And the results I need:
- Velocity
- Temperature
- Pressure
- Concentration (reactants, products and inert species) profiles.

If you´re confused because of the number of parameters I wrote down, here are the parameters of the first case I am trying to solve:

"physics": Empty pipe, premixed gases, laminar, adiabatic, no moving boundaries.
"chemistry": 2 reactants (CH4, O2), 1 inert (N2), 2 products (CO2, H2O), i.e. 1 simple reaction described by Arrhenius kinetics.

I am currently using reactingFoam but I can´t justify this choice and I don´t think it will do it for all the cases.

Can you tell me what solver I have to use depending on the system and, if not, what parameters to look at/for to choose it?
Let me know if you need further data to properly answer my question.

Thanks in advance.

Tibo

[francescomarra]

Dear Tibo,

sorry for my late answer.

I think you correctly choose to use reactingFoam to solve your first case.

There are some documents available in internet to find some indications about the use of OpenFOAM for premixed flames propagation.

One is the excellent website of Hani Kurser:
http://www.tfd.chalmers.se/~hani/kurser/OS_CFD/
Having a look to the projects of former students, you probably will find useful indications.

Another very interesting report by Christian Andersen and Niels E. L. Nielsen is available at the following link:
http://projekter.aau.dk/projekter/fi...784/Report.pdf
It contains also a description of the main OpenFOAM solvers for premixed combustion.

About your physical problem, despite the apparent simplicity of the configuration (a pipe open on both sides filled with an flammable mixture) the simulation could be not so easy. The main reason is that the laminar flame propagation is highly sensitive to the several disturbances that can be observed in the tube, depending on the actual boundary conditions (are you fixing a mass flow rate ?), tube length, and the flame (in)stability. As a result, different flame shapes (and therefore different flame propagation velocities and global combustion rates) can be observed, up to the point that symmetry can be lost.
It could be useful to select a configuration at the extremities of the tube that, at least initially, allows to select well defined boundary conditions.

Now, depending upon the phenomena you need to explore (flame quenching, flame shape, flame acceleration, etc.) you need to include a proper combustion model.

My best regards,

Franco

[megacrout]

Hi Francesco,

Thanks for your reply (again) and for your advise. I greatly appreciate it.

I had already found Andersen and Nielsen´s report as well as Chalmers website. They´re indeed pretty interesting but I did not spend a lot of time on any of them yet. Following your advise, I´ll have a closer look at them.

I´d be glad to read the answer of any Foamer opening this page.

Thanks in advance.

Tibo

[slakhapa]

Hello guys, I'm a chemical engineer, with focus in heterogeneous catalysis. While doing some internet search, I came across this thread. I see that you have, in the past, tried to develop a solver for catalytic converter or similar applications. I have just started looking into openFOAM for my modeling application and would really appreciate some help from you. If possible, I would really like to understand what solver you started with and was it successful. Would you be able to share your solver file for a test case? If not, I would still be interested in getting some help from you. That would be much appreciated. Let me know if you have any questions.

My email is satishlakhapatri@gmail.com.

Thank you in advance.
Satish, PhD

[shijin]

Can anyone tell me what solver I should use for steady in-compressible laminar non-premixed combustion ?