TY  - JOUR
A1  - Ewe, Hendrik
A1  - Klein, Peter
A1  - Pieper, Martin
A1  - Füldner, G.
T1  - Heat conductivity in sintered aluminium fibers
JF  - Cellular metals for structural and functional applications : CELLMET 2008 ; proceedings of the International Symposium on Cellular Metals for Structural and Functional Applications held October 8 - 10, 2008 in Dresden, Germany / ed. by Günter Stephani
Y1  - 2009
SP  - 187
EP  - 193
PB  - Fraunhofer IFAM
CY  - Dresden
ER  - 
TY  - JOUR
A1  - Pieper, Martin
A1  - Klein, Peter
T1  - A simple and accurate numerical network flow model for bionic micro heat exchangers
JF  - Heat mass transfer
Y1  - 2011
SN  - 0947-7411
VL  - 47
IS  - 5
SP  - 491
EP  - 503
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Pieper, Martin
A1  - Klein, Peter
T1  - Application of simple, periodic homogenization techniques to non-linear heat conduction problems in non-periodic, porous media
JF  - Heat mass transfer
N2  - Often, detailed simulations of heat conduction in complicated, porous media have large runtimes. Then homogenization is a powerful tool to speed up the calculations by preserving accurate solutions at the same time. Unfortunately real structures are generally non-periodic, which requires unpractical, complicated homogenization techniques. We demonstrate in this paper, that the application of simple, periodic techniques to realistic media, that are just close to periodic, gives accurate, approximative solutions. In order to obtain effective parameters for the homogenized heat equation, we have to solve a so called “cell problem”. In contrast to periodic structures it is not trivial to determine a suitable unit cell, which represents a non-periodic media. To overcome this problem, we give a rule of thumb on how to choose a good cell. Finally we demonstrate the efficiency of our method for virtually generated foams as well as real foams and compare these results to periodic structures.
Y1  - 2012
U6  - http://dx.doi.org/10.1007/s00231-011-0879-4
SN  - 0947-7411
VL  - 48
IS  - 2
SP  - 291
EP  - 300
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Pieper, Martin
A1  - Klein, Peter
T1  - Numerical solution of the heat equation with non-linear, time derivative-dependent source term
JF  - International Journal for Numerical Methods in Engineering
N2  - The mathematical modeling of heat conduction with adsorption effects in coated metal structures yields the heat equation with piecewise smooth coefficients and a new kind of source term. This term is special, because it is non-linear and furthermore depends on a time derivative. In our approach we reformulated this as a new problem for the usual heat equation, without source term but with a new non-linear coefficient. We gave an existence and uniqueness proof for the weak solution of the reformulated problem. To obtain a numerical solution, we developed a semi-implicit and a fully implicit finite volume method. We compared these two methods theoretically as well as numerically. Finally, as practical application, we simulated the heat conduction in coated aluminum fibers with adsorption in the zeolite coating. Copyright © 2010 John Wiley & Sons, Ltd.
Y1  - 2010
U6  - http://dx.doi.org/10.1002/nme.2937
SN  - 0029-5981
VL  - 84
IS  - 10
SP  - 1205
EP  - 1221
PB  - Wiley
CY  - Chichester
ER  -