% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@ARTICLE{Mauer:888363,
author = {Mauer, Georg},
title = {{H}ow {H}ydrogen {A}dmixture {C}hanges {P}lasma {J}et
{C}haracteristics in {S}pray {P}rocesses at {L}ow
{P}ressure},
journal = {Plasma chemistry and plasma processing},
volume = {41},
issn = {1572-8986},
address = {Dordrecht},
publisher = {Springer Science + Business Media B.V.},
reportid = {FZJ-2020-04869},
pages = {109-132},
year = {2021},
abstract = {In plasma spraying, hydrogen is widely used as a secondary
working gas besides argon. In particular under low pressure,
there are strong effects on the plasma jet characteristics
even by small hydrogen percentages. Under such conditions,
fundamental mechanisms like diffusion and recombination are
affected while this is less relevant under atmospheric
conditions. This was investigated for argon–hydrogen
mixtures by optical emission spectroscopy (OES). The small
electron densities under the investigated low pressure
conditions implied specific difficulties in the application
of several OES-based methods which are discussed in detail.
Adding hydrogen to the plasma gas effected an increased
plasma enthalpy. Moreover, the jet expanded radially as the
reactive part of the thermal conductivity was enhanced by
recombination of atomic hydrogen so that the shock waves
were less reflected at the cold jet rims. In the jet cores,
the lowest temperatures were found for the highest hydrogen
admixture because the energy consumption due to the
dissociation of molecular hydrogen outbalanced the increase
of the plasma enthalpy. Variations in the radial temperature
profiles were related to the jet structure and radial
thermal conductivity. The local hydrogen–argon
concentration ratios revealed an accumulation of hydrogen
atoms at the jet rims. Clear indications were found, that
higher hydrogen contents promoted the fast recombination of
electrons and ions. However, it is assumed that the
transport properties of the plasma were hardly affected by
this, since the electron densities and thus the ionization
degrees were generally small due to the low pressure
conditions},
cin = {IEK-1},
ddc = {540},
cid = {I:(DE-Juel1)IEK-1-20101013},
pnm = {113 - Methods and Concepts for Material Development
(POF3-113) / 1241 - Gas turbines (POF4-124)},
pid = {G:(DE-HGF)POF3-113 / G:(DE-HGF)POF4-1241},
typ = {PUB:(DE-HGF)16},
UT = {WOS:000595071400001},
doi = {10.1007/s11090-020-10143-6},
url = {https://juser.fz-juelich.de/record/888363},
}