|
[Sponsors] |
March 18, 2004, 06:39 |
about L-J Characteristic Length
|
#1 |
Guest
Posts: n/a
|
Who can tell me what is the L-J Characteristic Length and L-J Energy Parameter in the fluent software? How can I get the details about them, thank you very much!!!!!
|
|
March 18, 2004, 14:42 |
Re: about L-J Characteristic Length
|
#2 |
Guest
Posts: n/a
|
I accidentaly worked some time ago on Molecular Dynamics problems, so I should be able to answer this one..
Well, L-J stands for Lennard-Johnson potential, which describes the mutual forces that exist among atoms in a molecule. You can look in any textbook on solid state physics or kinetic theory of gases. (E.g. a classical reference from the first area: KITTEL, C.: Introduction to Solid State Physics, 5-th edition, John Willey & Sons Ltd., 1976) |
|
March 19, 2004, 01:23 |
Re: about L-J Characteristic Length
|
#3 |
Guest
Posts: n/a
|
Thank you very much, George. I get the book which you mentioned in the message. It just tells me what is the L-J potential, but how can i get the L-J Characteristic Length and L-J energy parameter. Do you know where i can get these parameters, or i have to calculate them according some formulations, and what's form of these formulations? Thank you,very very much!
|
|
March 22, 2004, 19:53 |
Re: about L-J Characteristic Length
|
#4 |
Guest
Posts: n/a
|
Kevin, Look at the transport database from Chemkin. The L-J parameters for many species are listed in there.
|
|
March 22, 2004, 20:00 |
Re: about L-J Characteristic Length
|
#5 |
Guest
Posts: n/a
|
cg,thank you very much! Can you tell me whether the chemkin is a software or a book? thanks a lot!
|
|
March 23, 2004, 08:07 |
Re: about L-J Characteristic Length
|
#6 |
Guest
Posts: n/a
|
thank you very much! i have got the answer from the chemkin. i have another question, what's the degrees of the freedom, where can i get the details about it? thank you very much@
|
|
March 23, 2004, 16:53 |
Re: about L-J Characteristic Length
|
#7 |
Guest
Posts: n/a
|
Hi Kevin, I wonder why are you taking such trouble investigating L-J potentials? Firstly, because the parameters (except perhaps for the number of degrees of freedom) are by no means possible to derive by you alone. And secondly, you need them only in order to be able to use kinetic theory of gases option for calculation of some physical properties. However, experimental data are substantially more accurate, namely if the database offers polynomial or piecewise polynomial approximation.
Regards George |
|
March 24, 2004, 21:53 |
Re: about L-J Characteristic Length
|
#8 |
Guest
Posts: n/a
|
Hello! Everyone , now i simulate a chemical reaction between gas(nh3) and porous solid(cacl2),but i met a problem in defining the material property. In the fluent, the unit of the standard state enthalpy and standard state entropy is j/kgmol and j/kgmol.k,respectively. But i search the unit of the stand state enthalpy and standard state entropy is j/mol and j/mol.k respectively. Who can tell me how to switch between these two units? Thank you very much!
|
|
March 25, 2004, 08:33 |
Re: about L-J Characteristic Length
|
#9 |
Guest
Posts: n/a
|
Hello! Everyone ,I met the problem about the Arrhenius Rate --1.How to get the Pre-Exponential Factor --2.How to calculate the Activation Energy --3.How to calculate Temperature Exponent
PS:I simulate the chemical reaction between the gas(nh3) and solid(cacl2) Thank you very much!!!! |
|
November 26, 2018, 19:39 |
|
#10 |
New Member
Anita Ringia
Join Date: Nov 2018
Posts: 1
Rep Power: 0 |
Hello Kevin,
How did you look at the transport database from Chemkin for The L-J parameters for many species Thank you |
|
December 6, 2018, 13:08 |
|
#11 |
Member
Emerson
Join Date: May 2018
Posts: 35
Rep Power: 7 |
I would like to know it too
|
|
December 6, 2018, 13:16 |
|
#12 |
Member
Emerson
Join Date: May 2018
Posts: 35
Rep Power: 7 |
||
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Deciding Characteristic Length | Caner | Main CFD Forum | 9 | December 9, 2010 11:04 |
Turbulent Characteristic Length/Turbulent Length Scale | fluentnoob | FLUENT | 2 | July 3, 2009 08:40 |
characteristic Length | CFD MAN | Main CFD Forum | 3 | September 11, 2002 07:26 |
Characteristic Length | CFD MAN | FLUENT | 0 | August 19, 2002 21:40 |
Characteristic Length Scale | Thomas P. Abraham | Main CFD Forum | 2 | April 20, 1999 17:16 |