TY  - JOUR
A1  - Schelthoff, Christof
A1  - Steffen, Bernhard
A1  - Weidner, Peter
A1  - Hoßfeld, Friedel
T1  - Hochauflösende Modellierung von SOFC-Brennstoffzellen / Schelthoff, Christof ; Steffen, Bernhard ; Weidner, Peter ; Hoßfeld, Friedel ; Divisek, J. ; Jung, Rita
JF  - Mathematik : Schlüsseltechnologie für die Zukunft ; Verbundprojekte zwischen Universität und Industrie ; mit 33 Tabellen / Karl-Heinz Hoffmann ... (Hrsg.)
Y1  - 1997
SN  - 3-540-61677-2
N1  - auch unter der Signatur 21 TLK 446 vorhanden
SP  - 105
EP  - 115
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Schelthoff, Christof
A1  - Steffen, Bernhard
T1  - Modellierung und Simulation am Beispiel von Hochtemperatur-Brennstoffzellen
JF  - Praxis der Informationsverarbeitung und Kommunikation : PIK. 19 (1996), H. 3
Y1  - 1996
SN  - 0930-5157
N1  - zugleich Interner Bericht KFA-ZAM-IB-9622 unter dem gleichen Titel
SP  - 138
EP  - 141
ER  - 
TY  - JOUR
A1  - Hirschfeld, Julian A.
A1  - Lustfeld, Hans
A1  - Reißel, Martin
A1  - Steffen, Bernhard
T1  - A novel scheme for precise diagnostics and effective stabilization of currents in a fuel cell stack
JF  - International Journal of Energy Research
N2  - A novel scheme for detecting inhomogeneous internal currents in a fuel cell stack is presented. In this paper the scheme is investigated for the case that the flow field plates consist of graphite. Then plates of high conductivity, e.g. aluminium between the flow field plates together with small slits in these plates have three effects: (a) Whenever a local inhomogeneity of the electric current occurs at a particular cell in the stack, this will induce a surface current close to that cell perpendicular to the averaged current. This current can be detected. (b) The plates of high conductivity completely prevent the inhomogeneities from spreading to neighbouring cells. (c) Even at the particular cell the inhomogeneity is suppressed as far as possible. Thus this scheme leads to much better diagnostic possibilities and at the same time reduces electric instabilities to an extent, where they probably become harmless. This scheme will first be explained for a simple model to clarify the idea. However, very precise three dimensional computations using realistic parameters are presented, corroborating the results of the simple model.
Y1  - 2010
U6  - https://doi.org/10.1002/er.1662
SN  - 0363-907X
VL  - 34
IS  - 3
SP  - 293
EP  - 301
PB  - Wiley
CY  - London
ER  - 
TY  - JOUR
A1  - Hirschfeld, Julian A.
A1  - Lustfeld, Hans
A1  - Reißel, Martin
A1  - Steffen, Bernhard
T1  - Tomographic diagnostics of current distributions in a fuel cell stack
JF  - International Journal of Energy Research
N2  - A novel tomographic scheme for analysing the state of any single membrane electrode assembly (MEA) in a stack is suggested. Plates of very high conductivity placed between every fuel cell and slitted in an appropriate manner cause surface currents at well-defined locations of the stack. We show that knowing these surface currents, information about anomalies of the currents in a MEA can be obtained using the methods of tomography. The results are mathematically not unique. However, when assuming plausible defect structures, one can exclude improbable deficiencies by applying a special form of simulated annealing. We present numerical calculations of typical examples demonstrating that the essential defects of the MEA in any single cell of the stack can be detected and their extent can be determined.
Y1  - 2010
U6  - https://doi.org/10.1002/er.1634
SN  - 0363-907X
VL  - 34
IS  - 3
SP  - 284
EP  - 292
PB  - Wiley
CY  - London
ER  - 
TY  - JOUR
A1  - Reißel, Martin
A1  - Lustfeld, Hans
A1  - Hirschfeld, Julian A.
A1  - Steffen, Bernhard
T1  - Uniqueness of magnetotomography for fuel cells and fuel cell stacks / Lustfeld, H. ; Hirschfeld, J. ; Reißel, M ; Steffen, B.
JF  - Journal of Physics A: Mathematical and Theoretical. 42 (2009), H.  495205
Y1  - 2009
SN  - 0022-3689
SP  - 9 S.
ER  - 
TY  - JOUR
A1  - Reißel, Martin
A1  - Lustfeld, Hans
A1  - Steffen, Bernhard
A1  - Schmidt, U.
T1  - Reconstruction of Electric Currents in a Fuel Cell by Magnetic Field Measurements / Lustfeld, H. ; Reißel, M. ; Steffen, B. ; Schmidt, U.
JF  - Journal of fuel cell science and technology
Y1  - 2009
SN  - 1550-624X
VL  - Vol. 6
IS  - Iss. 2
SP  - 021012-1
EP  - 021012-8
ER  - 
TY  - JOUR
A1  - Reißel, Martin
A1  - Hirschfeld, Julian A.
A1  - Lustfeld, Hans
A1  - Steffen, Bernhard
T1  - Magnetotomography and Electric Currents in a Fuel Cell / Lustfeld, H. ; Reißel, M. ; Steffen, B.
JF  - Fuel Cells. 9 (2009), H. 4
Y1  - 2009
SN  - 1615-6854
SP  - 474
EP  - 481
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Lustfeld, Hans
A1  - Hirschfeld, Julian A.
A1  - Reißel, Martin
A1  - Steffen, Bernhard
T1  - Enhancement of precision and reduction of measuring points in tomographic reconstructions
JF  - Physics Letters A
Y1  - 2011
SN  - 0375-9601
VL  - 375
IS  - 8
SP  - 1167
EP  - 1171
PB  - Elsevier
CY  - Amsterdam
ER  -