TY - CHAP A1 - Waldmann, Christoph A1 - Vera, Jean-Pierre de A1 - Dachwald, Bernd A1 - Strasdeit, Henry A1 - Sohl, Frank A1 - Hanff, Hendrik A1 - Kowalski, Julia A1 - Heinen, Dirk A1 - Macht, Sabine A1 - Bestmann, Ulf A1 - Meckel, Sebastian A1 - Hildebrandt, Marc A1 - Funke, Oliver A1 - Gehrt, Jan-Jöran T1 - Search for life in ice-covered oceans and lakes beyond Earth T2 - 2018 IEEE/OES Autonomous Underwater Vehicle Workshop, Proceedings November 2018, Article number 8729761 N2 - The quest for life on other planets is closely connected with the search for water in liquid state. Recent discoveries of deep oceans on icy moons like Europa and Enceladus have spurred an intensive discussion about how these waters can be accessed. The challenge of this endeavor lies in the unforeseeable requirements on instrumental characteristics both with respect to the scientific and technical methods. The TRIPLE/nanoAUV initiative is aiming at developing a mission concept for exploring exo-oceans and demonstrating the achievements in an earth-analogue context, exploring the ocean under the ice shield of Antarctica and lakes like Dome-C on the Antarctic continent. KW - Planetary exploration KW - Jupiter KW - ice moons KW - underwater vehicle KW - Antarctica Y1 - 2018 U6 - http://dx.doi.org/10.1109/AUV.2018.8729761 ER - TY - JOUR A1 - Schüller, K. A1 - Kowalski, Julia A1 - Raback, P. T1 - Curvilinear melting – A preliminary experimental and numerical study JF - International Journal of Heat and Mass Transfer N2 - When exploring glacier ice it is often necessary to take samples or implement sensors at a certain depth underneath the glacier surface. One way of doing this is by using heated melting probes. In their common form these devices experience a straight one-dimensional downwards motion and can be modeled by standard close-contact melting theory. A recently developed melting probe however, the IceMole, achieves maneuverability by simultaneously applying a surface temperature gradient to induce a change in melting direction and controlling the effective contact-force by means of an ice screw to stabilize its change in attitude. A modeling framework for forced curvilinear melting does not exist so far and will be the content of this paper. At first, we will extend the existing theory for quasi-stationary close-contact melting to curved trajectories. We do this by introducing a rotational mode. This additional unknown in the system implies yet the need for another model closure. Within this new framework we will focus on the effect of a variable contact-force as well as different surface temperature profiles. In order to solve for melting velocity and curvature of the melting path we present both an inverse solution strategy for the analytical model, and a more general finite element framework implemented into the open source software package ELMER. Model results are discussed and compared to experimental data conducted in laboratory tests. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.ijheatmasstransfer.2015.09.046 SN - 0017-9310 IS - 92 SP - 884 EP - 892 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Olaru, Alexandra Maria A1 - Kowalski, Julia A1 - Sethi, Vaishali A1 - Blümich, Bernhard T1 - Exchange relaxometry of flow at small Péclet numbers in a glass bead pack JF - Journal of Magnetic Resonance (JMR) N2 - In this paper we consider low Péclet number flow in bead packs. A series of relaxation exchange experiments has been conducted and evaluated by ILT analysis. In the resulting correlation maps, we observed a collapse of the signal and a translation towards smaller relaxation times with increasing flow rates, as well as a signal tilt with respect to the diagonal. In the discussion of the phenomena we present a mathematical theory for relaxation exchange experiments that considers both diffusive and advective transport. We perform simulations based on this theory and discuss them with respect to the conducted experiments. KW - NMR exchange relaxometry KW - Low-field NMR Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.jmr.2012.04.015 SN - 1096-0856 VL - 220 SP - 32 EP - 44 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Olaru, Alexandra Maria A1 - Kowalski, Julia A1 - Sethi, Vaishali A1 - Blümich, Bernhard T1 - Fluid Transport in Porous Media probed by Relaxation-Exchange NMR T2 - 2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec. Y1 - 2011 N1 - H12B-07; American Geophysical Union ER - TY - CHAP A1 - Niedermeier, H. A1 - Clemens, J. A1 - Kowalski, Julia A1 - Macht, S. A1 - Heinen, D. A1 - Hoffmann, R. A1 - Linder, Peter T1 - Navigation system for a research ice probe for antarctic glaciers T2 - IEEE/ION Position, Location and Navigation Symposium (PLANS) ; 5-8 May 2014, Monterey, Calif. Y1 - 2014 SN - 978-1-4799-3319-8 SP - 959 EP - 975 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - McArdell, Brian W. A1 - Bartelt, Perry A1 - Kowalski, Julia T1 - Field observations of basal forces and fluid pore pressure in a debris flow JF - Geophysical Research Letters (GRL) N2 - Using results from an 8 m2 instrumented force plate we describe field measurements of normal and shear stresses, and fluid pore pressure for a debris flow. The flow depth increased from 0.1 to 1 m within the first 12 s of flow front arrival, remained relatively constant until 100 s, and then gradually decreased to 0.5 m by 600 s. Normal and shear stresses and pore fluid pressure varied in-phase with the flow depth. Calculated bulk densities are ρb = 2000–2250 kg m−3 for the bulk flow and ρf = 1600–1750 kg m−3 for the fluid phase. The ratio of effective normal stress to shear stress yields a Coulomb basal friction angle of ϕ = 26° at the flow front. We did not find a strong correlation between the degree of agitation in the flow, estimated using the signal from a geophone on the force plate, and an assumed dynamic pore fluid pressure. Our data support the idea that excess pore-fluid pressures are long lived in debris flows and therefore contribute to their unusual mobility. KW - debris flow Y1 - 2007 SN - 0094-8276 VL - 34 IS - 7 ER - TY - JOUR A1 - Lyons, W. Berry A1 - Mikucki, Jill A. A1 - German, Laura A. A1 - Welch, Kathleen A. A1 - Welch, Susan A. A1 - Gardener, Christopher B. A1 - Tulaczyk, Slawek M. A1 - Pettit, Erin C. A1 - Kowalski, Julia A1 - Dachwald, Bernd T1 - The Geochemistry of Englacial Brine from Taylor Glacier, Antarctica JF - Journal of Geophysical Research: Biogeosciences Y1 - 2019 U6 - http://dx.doi.org/10.1029/2018JG004411 SN - 2169-8961 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Kowalski, Julia A1 - McElwaine, Jim N. T1 - Shallow two-component gravity-driven flows with vertical variation JF - Journal of Fluid Mechanics Y1 - 2013 SN - 0022-1120 VL - 714 SP - 434 EP - 462 PB - Cambridge Univ. Press CY - Cambridge ER - TY - CHAP A1 - Kowalski, Julia A1 - McElwaine, J. T1 - Two-phase debris flow modeling T2 - Geophysical Research Abstracts Y1 - 2008 N1 - A-01048 ER - TY - CHAP A1 - Kowalski, Julia A1 - McArdell, B. W. A1 - Bartelt, Perry T1 - A comparison of two approaches to modeling multiphase gravity currents T2 - Geophysical Research Abstracts Y1 - 2006 N1 - A-08738 VL - 8 ER -