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Turbulenter Wärme‐ und Stoffaustausch
Author(s) -
Jischa Michael
Publication year - 1983
Publication title -
chemie ingenieur technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.365
H-Index - 36
eISSN - 1522-2640
pISSN - 0009-286X
DOI - 10.1002/cite.330550307
Subject(s) - turbulence , mechanics , physics , momentum transfer , momentum (technical analysis) , reynolds stress , heat transfer , churchill–bernstein equation , k epsilon turbulence model , mass transfer , statistical physics , reynolds number , classical mechanics , optics , nusselt number , finance , scattering , economics
Turbulent heat and mass transfer . Turbulent heat and mass transfer is inseparably connected with turbulent momentum transfer. Thus we again find the same problems as those encountered in the description of turbulent momentum transfer. Moreover, further difficulties arise because of the temperature and concentration fluctuations in addition to the velocity and pressure fluctuations. The problems are essentially experimental ones. It is much simpler to measure correlations of velocity fluctuations like the turbulence energy or the Reynolds shear stress than correlations of other fluctuating quantities. This is why attempts were made at an early stage to reduce the turbulent heat and mass transfer to the comparatively well understood turbulent transfer of momentum. Therefore the basic ideas concerning the modelling of the turbulent momentum flux are discussed at first. A brief introduction to concepts of the statistical theory of turbulence is also given. Finally some proposals to describe the turbulent heat transfer based on modelling assumptions are presented for example of turbulent tube flow. Turbulent mass transfer is only briefly touched upon because of the far greater experimental gaps opposing reliable modelling.