View Issue Details

IDProjectCategoryView StatusLast Update
0001008OpenFOAMBugpublic2014-02-18 09:20
Reporteruser19Assigned Touser2 
Status resolvedResolutionno change required 
Summary0001008: UserGuide gives wrong relation between absolute and sensible enthalpy
DescriptionThe UserGuide (p. 181, eq. 7.1) specifies

h = h_s + \sum_i c_i \Delta h_f^i

where c_i is said to be the molar fraction. This is clearly wrong, and c_i should be the mass fraction instead (commonly Y_i). See e.g. Kuo, "FUNDAMENTALS OF TURBULENT AND MULTIPHASE COMBUSTION", 2012, p. 19, table 1.4)
TagsNo tags attached.



2013-09-12 18:02

reporter   ~0002487

OpenFOAM uses internally units [J/kmol] for enthalpy, hence the mole averaging. This could probably be mentioned in the user guide.

In the source code, typically upper case letters (e.g. Ha) indicate [J/kg] and lower case (e.g. ha) [J/kmol].

see also:


2013-09-13 05:16


Last edited: 2013-09-13 05:16

Ah, yes, in that case it is correct. I agree, though, that this certainly should be mentioned in the user guide.


2014-02-18 09:20


not a bug in OpenFOAM

Issue History

Date Modified Username Field Change
2013-09-12 17:33 user19 New Issue
2013-09-12 18:02 dkxls Note Added: 0002487
2013-09-13 05:16 user19 Note Added: 0002489
2013-09-13 05:16 user19 Note Edited: 0002489
2014-02-18 09:20 user2 Note Added: 0002840
2014-02-18 09:20 user2 Status new => resolved
2014-02-18 09:20 user2 Resolution open => no change required
2014-02-18 09:20 user2 Assigned To => user2