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You searched for +publisher:"University of Twente" +contributor:("Weinhart, Thomas"). Showing records 1 – 2 of 2 total matches.

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1. Roy, Sudeshna. Hydrodynamic theory of wet particle systems.

Degree: 2018, University of Twente

External forces lead to granular flow under the condition that the applied shear stress reaches the yield (shear) stress while another stress must be maintained for continuous flow in steady state. Most studies in granular physics focus on dry granular materials and their flow rheology. However, wet granular materials are ubiquitous in geology and many real world applications where interstitial liquid is present between the grains. There are several proposals for flow rules of dry and wet granular materials available in the literature. These flow rules differ in complexity and in the number of parameters, which are combined in the equations. The main focus areas of my research are (i) the formulation of suitable constitutive equations for the hydrodynamic density-stress-strain relations, specifically for wet granular materials, (ii) the deduction of the constitutive equations from discrete element simulations, and (iii) the validation of the micro-macro transition with numerical, theoretical and experimental results. The geometrical set-up of split-bottom shear cell used in my research is most appropriate for assessing the shear band originating from the split position that widens near the free surface. My research proposes a modified generalized flow rule/rheology to close the fundamental conservation laws for mass and momentum. Subsequently, a correlation is developed between the micro parameters and the {steady state cohesion in the limit} of very low confining pressure. Another aspect of studying unsaturated granular media is the movement of interstitial liquid due to the rupture of existing and formation of new liquid bridges. Shearing a wet granular system causes a re-distribution and transport of the interstitial liquid. The liquid transport can be modeled by a diffusion equation with a space-dependent diffusive coefficient in the split bottom geometry. Alternatively, it is shown here that this is an advective-diffusive process with constant diffusivity coefficient and a space-dependent drift, when transformed to an appropriate set of variables that can be solved analytically. The final chapter of this thesis concerns the experimental work exploring the surface flow profile for different dry and wet granular materials. Advisors/Committee Members: Luding, Stefan, Weinhart, Thomas.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Roy, S. (2018). Hydrodynamic theory of wet particle systems. (Doctoral Dissertation). University of Twente. Retrieved from https://research.utwente.nl/en/publications/hydrodynamic-theory-of-wet-particle-systems(7ec22596-a370-45f7-bdf5-531892661a45).html ; urn:nbn:nl:ui:28-7ec22596-a370-45f7-bdf5-531892661a45 ; 7ec22596-a370-45f7-bdf5-531892661a45 ; 10.3990/1.9789036544689 ; urn:isbn:978-90-365-4468-9 ; urn:nbn:nl:ui:28-7ec22596-a370-45f7-bdf5-531892661a45 ; https://research.utwente.nl/en/publications/hydrodynamic-theory-of-wet-particle-systems(7ec22596-a370-45f7-bdf5-531892661a45).html

Chicago Manual of Style (16th Edition):

Roy, Sudeshna. “Hydrodynamic theory of wet particle systems.” 2018. Doctoral Dissertation, University of Twente. Accessed September 21, 2020. https://research.utwente.nl/en/publications/hydrodynamic-theory-of-wet-particle-systems(7ec22596-a370-45f7-bdf5-531892661a45).html ; urn:nbn:nl:ui:28-7ec22596-a370-45f7-bdf5-531892661a45 ; 7ec22596-a370-45f7-bdf5-531892661a45 ; 10.3990/1.9789036544689 ; urn:isbn:978-90-365-4468-9 ; urn:nbn:nl:ui:28-7ec22596-a370-45f7-bdf5-531892661a45 ; https://research.utwente.nl/en/publications/hydrodynamic-theory-of-wet-particle-systems(7ec22596-a370-45f7-bdf5-531892661a45).html.

MLA Handbook (7th Edition):

Roy, Sudeshna. “Hydrodynamic theory of wet particle systems.” 2018. Web. 21 Sep 2020.

Vancouver:

Roy S. Hydrodynamic theory of wet particle systems. [Internet] [Doctoral dissertation]. University of Twente; 2018. [cited 2020 Sep 21]. Available from: https://research.utwente.nl/en/publications/hydrodynamic-theory-of-wet-particle-systems(7ec22596-a370-45f7-bdf5-531892661a45).html ; urn:nbn:nl:ui:28-7ec22596-a370-45f7-bdf5-531892661a45 ; 7ec22596-a370-45f7-bdf5-531892661a45 ; 10.3990/1.9789036544689 ; urn:isbn:978-90-365-4468-9 ; urn:nbn:nl:ui:28-7ec22596-a370-45f7-bdf5-531892661a45 ; https://research.utwente.nl/en/publications/hydrodynamic-theory-of-wet-particle-systems(7ec22596-a370-45f7-bdf5-531892661a45).html.

Council of Science Editors:

Roy S. Hydrodynamic theory of wet particle systems. [Doctoral Dissertation]. University of Twente; 2018. Available from: https://research.utwente.nl/en/publications/hydrodynamic-theory-of-wet-particle-systems(7ec22596-a370-45f7-bdf5-531892661a45).html ; urn:nbn:nl:ui:28-7ec22596-a370-45f7-bdf5-531892661a45 ; 7ec22596-a370-45f7-bdf5-531892661a45 ; 10.3990/1.9789036544689 ; urn:isbn:978-90-365-4468-9 ; urn:nbn:nl:ui:28-7ec22596-a370-45f7-bdf5-531892661a45 ; https://research.utwente.nl/en/publications/hydrodynamic-theory-of-wet-particle-systems(7ec22596-a370-45f7-bdf5-531892661a45).html

2. Denissen, Irana Francisca Catharina. On segregation in bidisperse granular flows.

Degree: 2019, University of Twente

Every year, thousands of people die due to landslides, avalanches and other natural disasters in which separate particles play an important role. For accurate zonation and risk assessment, efficient models are needed that not only take into account the basal topo-graphy, but also the properties of these particles (snow, rock, sand, etc.), such as size- and shape-distribution. The conglomoration of particles is called a granular material, and the flow of a granular material is a granular flow. When a granular material is composed of multiple components that differ in e.g. size, density or shape, the mixture usually segregates into separate phases when sheared or shaken. For example in a size-bidisperse flow over an inclined plane, which contains large and small particles, the larger particles tend to the free surface, while the small particles tend to the base. Both the cause of segregation and the phenomenological aspects are active areas of research. This thesis looks at the latter; it aims to develop efficient and accurate models of granular flows, in particular of bidisperse granular flows, which consist of two types of particles. This thesis starts with developing an efficient model monodisperse granular flows through a contraction, which is validated with a more complex model. This is followed by a model for size-bidisperse flows over an uniform channel, which shows the bulbous head as emergent segregation structure. Then a new technique for mapping discrete particle data to continuum fields is presented, and finally the segregation behaviour of shape-bidisperse particles with different elongations is studied. Advisors/Committee Members: Thornton, Anthony Richard, Weinhart, Thomas.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Denissen, I. F. C. (2019). On segregation in bidisperse granular flows. (Doctoral Dissertation). University of Twente. Retrieved from https://research.utwente.nl/en/publications/on-segregation-in-bidisperse-granular-flows(84cb3083-4e45-47ba-bac5-cc51880e8601).html ; urn:nbn:nl:ui:28-84cb3083-4e45-47ba-bac5-cc51880e8601 ; 84cb3083-4e45-47ba-bac5-cc51880e8601 ; 10.3990/1.9789036548762 ; urn:isbn:978-90-365-4876-2 ; urn:isbn:978-90-365-4876-2 ; urn:nbn:nl:ui:28-84cb3083-4e45-47ba-bac5-cc51880e8601 ; https://research.utwente.nl/en/publications/on-segregation-in-bidisperse-granular-flows(84cb3083-4e45-47ba-bac5-cc51880e8601).html

Chicago Manual of Style (16th Edition):

Denissen, Irana Francisca Catharina. “On segregation in bidisperse granular flows.” 2019. Doctoral Dissertation, University of Twente. Accessed September 21, 2020. https://research.utwente.nl/en/publications/on-segregation-in-bidisperse-granular-flows(84cb3083-4e45-47ba-bac5-cc51880e8601).html ; urn:nbn:nl:ui:28-84cb3083-4e45-47ba-bac5-cc51880e8601 ; 84cb3083-4e45-47ba-bac5-cc51880e8601 ; 10.3990/1.9789036548762 ; urn:isbn:978-90-365-4876-2 ; urn:isbn:978-90-365-4876-2 ; urn:nbn:nl:ui:28-84cb3083-4e45-47ba-bac5-cc51880e8601 ; https://research.utwente.nl/en/publications/on-segregation-in-bidisperse-granular-flows(84cb3083-4e45-47ba-bac5-cc51880e8601).html.

MLA Handbook (7th Edition):

Denissen, Irana Francisca Catharina. “On segregation in bidisperse granular flows.” 2019. Web. 21 Sep 2020.

Vancouver:

Denissen IFC. On segregation in bidisperse granular flows. [Internet] [Doctoral dissertation]. University of Twente; 2019. [cited 2020 Sep 21]. Available from: https://research.utwente.nl/en/publications/on-segregation-in-bidisperse-granular-flows(84cb3083-4e45-47ba-bac5-cc51880e8601).html ; urn:nbn:nl:ui:28-84cb3083-4e45-47ba-bac5-cc51880e8601 ; 84cb3083-4e45-47ba-bac5-cc51880e8601 ; 10.3990/1.9789036548762 ; urn:isbn:978-90-365-4876-2 ; urn:isbn:978-90-365-4876-2 ; urn:nbn:nl:ui:28-84cb3083-4e45-47ba-bac5-cc51880e8601 ; https://research.utwente.nl/en/publications/on-segregation-in-bidisperse-granular-flows(84cb3083-4e45-47ba-bac5-cc51880e8601).html.

Council of Science Editors:

Denissen IFC. On segregation in bidisperse granular flows. [Doctoral Dissertation]. University of Twente; 2019. Available from: https://research.utwente.nl/en/publications/on-segregation-in-bidisperse-granular-flows(84cb3083-4e45-47ba-bac5-cc51880e8601).html ; urn:nbn:nl:ui:28-84cb3083-4e45-47ba-bac5-cc51880e8601 ; 84cb3083-4e45-47ba-bac5-cc51880e8601 ; 10.3990/1.9789036548762 ; urn:isbn:978-90-365-4876-2 ; urn:isbn:978-90-365-4876-2 ; urn:nbn:nl:ui:28-84cb3083-4e45-47ba-bac5-cc51880e8601 ; https://research.utwente.nl/en/publications/on-segregation-in-bidisperse-granular-flows(84cb3083-4e45-47ba-bac5-cc51880e8601).html

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