Kolumban Hutter

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Hutter

First Name

Kolumban

ORCID

0000-0003-4512-5264

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Publications 1 - 10 of 43

Important aspects in the formulation of solid–fluid debris-flow models. Part I. Thermodynamic implications
Hutter, Kolumban; Schneider, Lukas (2010)
Continuum Mechanics and Thermodynamics
A viscoelastic Rivlin-Ericksen material model applicable to glacier ice
Riesen, Patrick; Hutter, Kolumban; Funk, Martin (2010)
Nonlinear Processes in Geophysics
We present a viscoelastic constitutive relation which describes transient creep of a modified second grade fluid enhanced with elastic properties of a solid. The material law describes a Rivlin-Ericksen material and is a generalization of existing material laws applied to study the viscoelastic properties of ice. The intention is to provide a formulation tailored to reproduce the viscoelastic behaviour of ice ranging from the instantaneous elastic response, to recoverable deformation, to viscous, stationary flow at the characteristic minimum creep rate associated with the deformation of polycrystalline ice. We numerically solve the problem of a slab of material shearing down a uniformly inclined plate. The equations are made dimensionless in a form in which elastic effects and/or the influence of higher order terms (i.e., strain accelerations) can be compared with viscous creep at the minimum creep rate by means of two dimensionless parameters. We discuss the resulting material behaviour and the features exhibited at different parameter combinations. Also, a viable range of the non-dimensional parameters is estimated in the scale analysis.
Thermal response of unconfined ice shelves to climatic conditions
Williams, F. Mary; Hutter, Kolumban (1983)
Acta Mechanica
An analysis of the thermomechanical behavior of an ice shelf is presented. The mathematics is simplified by simulating the transverse temperature distribution by a realistic shape function thereby replacing the local energy equation by a time-dependent, total energy balance condition which accurately models the ocean-ice and ice-atmosphere heat exchange processes. The emerging steady state theory correlates a dimensionless combination of accumulation rate, horizontal strain rate and thickness with heat flux and surface temperature and shows fair agreement with published data. A time-dependent small perturbation analysis further shows that the criterion of stability of the solutions is expressible in terms of this dimensionless parameter. Stable and unstable flow regimes can be separated and physically interpreted.
Phenomenological Thermodynamics of Irreversible Processes
Wang, Yongqi; Hutter, Kolumban (2018)
Entropy
One-dimensional models for topographic Rossby waves in elongated basins on the f-plane
Stocker, Thomas; Hutter, Kolumban (1986)
Journal of Fluid Mechanics
Topographic Rossby waves in elongated basins on the f-plane are studied by transforming the linear boundary-value problem for the mass transport stream function into a class of two-point boundary-value problems of which the independent spatial variable is the (curved) basin axis. The procedure for deriving the substitute problems is the Method of Weighted Residuals. What emerges is a vector differential equation and associated boundary conditions, its dimension indicating the order of the approximate model. It is shown that each substitute problem in the class entails the qualitative features typical of topographic waves, and increasing the order of the model corresponds to higher-order approximations. Equations are explicitly presented for cross-sectional distributions of the lake topography which has a power-law representation and permits the analysis of weak and strong topographies. Straight channels in which the depth profile does not change with position along the axis are studied in detail. The dispersion relation is discussed and dispersion curves are shown for the three lowest-order models. Convergence properties are thereby uncovered and phase speed and group velocity properties are found as they depend on wavenumber and topography. Further, for the lowest two modes, cross-channel stream-function distributions are presented. Apart from further convergence properties these distributions show that for U-shaped channels wave activity is nearer to the shore than for V-shaped channels, important information in the design of mooring systems. An analysis of topographic Rossby wave reflection follows, which emphasizes the importance of the depth profile in the reflecting zone. Based on these results some lake solutions are presented.
Avalanche dynamics. Review of experiments and theoretical models of flow and powder snow avalanches
Scheiwiller, Thomas; Hutter, Kolumban (1983)
Journal of Glaciology
The paper of which this is an extended abstract reviews theoretical formulations for flow and airborne powder-snow avalanches. First powder-snow avalanches are considered as plane turbulent gravity currents. Then we propose a two-phase model describing powder-snow avalanches as turbulent binary mixtures of snow granules and air. An analogy is postulated between flow avalanches and the rapid shear flow of granular materials which leads to a non-polar continuum with microstructure taking into account the fluctuation energy of the snow granules.
Correspondence between de Saint-Venant and Boussinesq
Hager, Willi H.; Hutter, Kolumban; Castro-Orgaz, Oscar (2022)
The research of Boussinesq entitled ‘Essay on the theory of flowing water’ is certainly one of his key works. It was decided to publish it not as a book but rather as a contribution to the Mémoires de l’Académie de sciences, the French top journal of the 19th century. To be accepted in it, a Report of the president of the Mechanics Section of the Academy had to generate a positive evaluation. Given that Saint-Venant was its president, and that he supported the publication of his colleague Boussinesq in the Mémoires, this was no further problem. However, it took 5 years from the positive Report until the Essay was finally published. In addition, it was not published in one volume, but in two issues of the Mémoires. How come these complications, and what is the background of the contents of the Essay? This research aims to clarify several aspects, based on (1) Saint-Venant’s Report on the Essay thereby detailing its contents, and (2) the Correspondence between the two outstanding scientists of the late 19th century. It is concluded that the Essay on the one hand is highly complex to understand mainly due to the writing style of Boussinesq, and that it contains excellent issues on the venue how challenging problems such as flows with a significant streamline curvature or water waves of finite depth may be solved based both on a physical approach paired with suitable approximations. These finally allowed for solutions of problems such as the solitary wave or the formulation of the Boussinesq equations based on the momentum conservation both for the cases without and with regard to streamline curvature effects.
Topographic waves in rectangular basins
Stocker, Thomas; Hutter, Kolumban (1987)
Journal of Fluid Mechanics
The channel model of Stocker & Hutter (1986, 1987) is used to construct topographic wave solutions in a rectangular basin on the f-plane with variable but symmetric bathymetry. We show that in a narrow period band three types of eigenmodes can be discerned which exhibit local, midscale and global structure, respectively. Wave motion can be trapped either at the long sides of the elongated basin (channel mode) or at the ends of it (bay mode) or alternatively, a basinwide phase rotation is observed (Ball mode). The new bay modes are explained as resonances of topographic wave reflection in a semi-infinite channel. The influence of the variation of the aspect ratio of the rectangle and the topography parameter on the wave periods is also investigated.
A thermodynamic theory of fluids and solids in electromagnetic fields
Hutter, Kolumban (1977)
Archive for Rational Mechanics and Analysis
A thermodynamic theory for the description of a polarizable and magnetizable fluid and solid is presented in which the absolute temperature is not a primitive but a derived quantity. The electromagnetic field equations and the electromechanical interaction terms are based on the so-called Chu-formulation, in which magnetization is based on a dipole model. It is shown in this theory that entropy flux equals heat flux divided by the absolute temperature. Furthermore, the Gibbs relation is a proved consequence of the application of the entropy principle adopted here. The theory is developed first for a heat conducting fluid and then for a viscous thermoelastic solid. For both, internal energy, equilibrium stress and entropy can be decomposed into two parts, one of which is due to the electromagnetic fields, while the other is the well known thermodynamic part in the absence of electromagnetic fields. The paper closes with a comparison of this theory with other thermodynamic interaction models.
Elements of a computational theory for glaciers
Yakowitz, Sydney; Hutter, Kolumban; Szidarovszky, Ferenc (1986)
Journal of Computational Physics
In recent years, theoretical glaciologists have derived a complete and highly credible model for ice masses. The model is based on standard conservation laws of physics as well as measured constitutive relations of ice. In this model, mechanical and thermal effects interact through nonlinear creep response laws, and the end product is a system of nonlinear partial differential equations with a free boundary condition. This model is easy enough to relate, but is probably intractible, analytically, and is far from trivial, computationally. This paper describes our strategy for solving a restricted, but nevertheless informative case: the uniaxial, cold, shallow, steady-state ice sheet with an idealized geometry. The authors believe that theirs is the first solution of the fully coupled equations. The details of a particular ice sheet computation are given, and qualitative implications are drawn. The computations go far toward settling some controversies in the glaciology literature, and bring to light questionable aspects of the “shallow ice” approximation.

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Kolumban Hutter

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