TY - JOUR A1 - Vogt, C. A1 - Mottaghy, Darius A1 - Wolf, A. A1 - Rath, V. A1 - Pechnig, R. A1 - Clauser, C. T1 - Reducing temperature uncertainties by stochastic geothermal reservoir modelling JF - Geophysical Journal International N2 - Quantifying and minimizing uncertainty is vital for simulating technically and economically successful geothermal reservoirs. To this end, we apply a stochastic modelling sequence, a Monte Carlo study, based on (i) creating an ensemble of possible realizations of a reservoir model, (ii) forward simulation of fluid flow and heat transport, and (iii) constraining post-processing using observed state variables. To generate the ensemble, we use the stochastic algorithm of Sequential Gaussian Simulation and test its potential fitting rock properties, such as thermal conductivity and permeability, of a synthetic reference model and—performing a corresponding forward simulation—state variables such as temperature. The ensemble yields probability distributions of rock properties and state variables at any location inside the reservoir. In addition, we perform a constraining post-processing in order to minimize the uncertainty of the obtained distributions by conditioning the ensemble to observed state variables, in this case temperature. This constraining post-processing works particularly well on systems dominated by fluid flow. The stochastic modelling sequence is applied to a large, steady-state 3-D heat flow model of a reservoir in The Hague, Netherlands. The spatial thermal conductivity distribution is simulated stochastically based on available logging data. Errors of bottom-hole temperatures provide thresholds for the constraining technique performed afterwards. This reduce the temperature uncertainty for the proposed target location significantly from 25 to 12 K (full distribution width) in a depth of 2300 m. Assuming a Gaussian shape of the temperature distribution, the standard deviation is 1.8 K. To allow a more comprehensive approach to quantify uncertainty, we also implement the stochastic simulation of boundary conditions and demonstrate this for the basal specific heat flow in the reservoir of The Hague. As expected, this results in a larger distribution width and hence, a larger, but more realistic uncertainty estimate. However, applying the constraining post-processing the uncertainty is again reduced to the level of the post-processing without stochastic boundary simulation. Thus, constraining post-processing is a suitable tool for reducing uncertainty estimates by observed state variables. Y1 - 2010 U6 - http://dx.doi.org/10.1111/j.1365-246X.2009.04498.x SN - 1365-246X VL - 181 IS - 1 SP - 321 EP - 333 PB - Oxford University Press CY - Oxford 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 - TY - JOUR A1 - Mottaghy, Darius A1 - Pechnig, Renate A1 - Taugs, Renate A1 - Kröger, Jens A1 - Thomsen, Claudia A1 - Hesse, Fabian A1 - Liebsch-Doerschner, Thomas T1 - Erstellung eines geothermischen Modells für Teile Hamburgs und anliegende Gebiete JF - BBR - Fachmagazin für Brunnen- und Leitungsbau Y1 - 2010 SN - 1611-1478 VL - 61 IS - 12 SP - 52 EP - 59 PB - WVGW Wirtschafts- u. Verl.Ges. Gas und Wasser CY - Bonn ER - TY - JOUR A1 - Kern, Alexander A1 - Schelthoff, Christof A1 - Mathieu, Moritz T1 - Die dynamische Blitzkugel : Wahrscheinlichkeitsberechnung für Blitzeinschläge in Gebäude JF - De Fachzeitschrift für das Elektrohandwerk. 13-14 (2010) Y1 - 2010 SP - 24 EP - 29 ER - TY - JOUR A1 - Kern, Alexander A1 - Schelthoff, Christof A1 - Mathieu, Moritz T1 - Probability of lightning strikes to air-terminations of structures using the electro-geometrical model theory and the statistics of lightning current parameters Y1 - 2010 N1 - 30th International Conference on Lightning Protection, Cagliari (Italien), 2010 SP - 750-1 EP - 750-8 ER - TY - JOUR A1 - Kern, Alexander A1 - Klöters, Georg A1 - Pferdemenges, Jörg T1 - Optimised protection against lightning for the signalling and safety systems of level crossings on non-electrified railway lines JF - RTR : European Rail Technology Review Y1 - 2010 SN - 0079-9548 VL - 50 IS - 2 ER - TY - JOUR A1 - Kern, Alexander A1 - Frentzel, Ralf A1 - Behrens, Jörg T1 - Simulation of the transient voltages in the auxiliary power network of a large power plant in case of a direct lightning strike to the high-voltage overhead transmission line Y1 - 2010 N1 - 30th International Conference on Lightning Protection, Cagliari (Italien), 2010 SP - 749-1 EP - 749-7 ER - TY - JOUR A1 - Goldbach, Daniel T1 - Fahrstabilitätserhöhung bei Gespannen durch Querverschiebung des Anhängerkupplungspunktes JF - mechatronik mobil Y1 - 2010 SN - 1867-7371 VL - 2 IS - 1 SP - 23 EP - 29 PB - Expert Verlag CY - Renningen ER - TY - JOUR A1 - Geimer, Konstantin A1 - Sauerborn, Markus A1 - Hoffschmidt, Bernhard A1 - Schmitz, Mark A1 - Göttsche, Joachim T1 - Test Facility for Absorber Specimens of Solar Tower Power Plants JF - Advances in Science and Technology. 74 (2010) Y1 - 2010 N1 - 5th Forum on New Materials : CIMTEC 2010, Montecatini Terme, Italy 13-18 June 2010. Part C SP - 266 EP - 271 ER - TY - JOUR A1 - Fleischhaker, Robert A1 - Evers, Jörg A1 - Dey, Tarak N. T1 - Phase modulation induced by cooperative effects in electromagnetically induced transparency JF - Physical Review A - Atomic, molecular, and optical physics N2 - We analyze the influence of dipole-dipole interactions in an electromagnetically induced transparency set up for a density at the onset of cooperative effects. To this end, we include mean-field models for the influence of local-field corrections and radiation trapping into our calculation. We show both analytically and numerically that the polarization contribution to the local field strongly modulates the phase of a weak pulse. We give an intuitive explanation for this local-field-induced phase modulation and demonstrate that it distinctively differs from the nonlinear self-phase-modulation that a strong pulse experiences in a Kerr medium. Y1 - 2010 U6 - http://dx.doi.org/10.1103/PhysRevA.82.013815 SN - 1050-2947 VL - 82 IS - 1 PB - AIP Publishing CY - Melville, NY ER -