|
[Sponsors] |
OpenFOAM: sensible enthalpy/internal energy for a reactive case |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
August 15, 2022, 05:17 |
OpenFOAM: sensible enthalpy/internal energy for a reactive case
|
#1 |
Member
K
Join Date: Jul 2017
Posts: 97
Rep Power: 9 |
Hi foamers,
I have a question regarding the calculation of the sensible enthalpy/interal energy. I first start by explaining what I expect to see in the algorithem based on thermodynamic text books and after, I 'll compare it with the codes in OpenFoam. For an inviscid/adiabatique reactive case exchanging no work with the environment, we have: with where and are, respectively, the enthalpy of formation of species i and the mass fraction of species i. In the same way, can be calculated; However, as the nature of species change in presence of chemical reactions, for enthalpy (the same applies for internal energy) we HAVE to take a reference. The standard reference is = 25°C and = 1 atm. As such h, is calculated based on a reference value: Now, my question is how this reference temperature is considered in OpenFOAM (we know that the sensible enthalpy/interal energy do not change a lot with pressure). I cannot find any track of this reference temperature in OpenFOAM. For instance, if we take a look at temperature calculation based on Newton’s method in src/thermophysicalModels/specie/thermo/thermo/thermoI.H, we have something as*: However, we know that: Therefore: We know that is different from and we can NOT have the following simplification: to deduce: I would be grateful if someone could explain that to me. Am I missing a step here? P.S.: I read carefully http://caefn.com/openfoam/temperature-calculation and tried to search a lot on different forums. But, I could not find my answer there. * that expression is coming from Temperature calculation from sensible internal energy . Last edited by mkhm; August 15, 2022 at 08:05. |
|
Tags |
inviscid flow, openfaom, reacting flow, sensible heat transfer, sensibleenthalpy |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
[Tutorials] How to prepare a case for OpenFOAM (for beginners) | taalf | OpenFOAM Community Contributions | 1 | November 6, 2022 02:22 |
Map of the OpenFOAM Forum - Understanding where to post your questions! | wyldckat | OpenFOAM | 10 | September 2, 2021 06:29 |
Some problems in naca 0012 V&V case of NASA TMR and DPW using OpenFOAM | chengdi | OpenFOAM Running, Solving & CFD | 7 | October 5, 2019 14:20 |
Free surface boudary conditions with SOLA-VOF | Fan | Main CFD Forum | 10 | September 9, 2006 13:24 |
Why FVM for high-Re flows? | Zhong Lei | Main CFD Forum | 23 | May 14, 1999 14:22 |