Anomalous intruder response in diverse granular systems

Loreto Alejandra Oyarte Galvez

Research output: ThesisPhD Thesis - Research UT, graduation UTAcademic

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Abstract

The definition of granular matter is extremely broad; any collection of conglomeration of particles larger than 100 micrometers can be considered as part of this group, and virtually the entire universe is composed of them. Examples are found in many fields, e.g. in nature (dunes, avalanches, asteroids, etc.), industry (preparation of medicines, manufacture of concretes, paints, etc.), and even food (corn, wheat, etc.). As a result, its applications are very varied and numerous, and undoubtedly constitute an important focus of study for scientists. In this thesis, we attempted to understand and describe granular materials probing three distinct granular systems with an intruder. (i) In our first system, we study the impact and settling of a sphere in a suspension of cornstarch in which the suspending fluid is gradually changed from pure water to pure ethanol. We show that partly replacing water by ethanol strongly alters the suspension rheology, turning the suspension from a strongly shear-thickening fluid into its opposite: a shear-thinning liquid. We relate the macroscopic behaviour to the microscopic details of the grain-grain interaction using atomic force microscopy. (ii) In our second system, we build a rotor similar to the famous Smoluchowski-Feynman device, which is immersed in a granular gas and experimentally study the behaviour of its angular velocity distribution. We find that the existing models are not capable of adequately describing the experimentally observed distribution. However, we show that incorporating the effects of the external friction and the collision rate experienced by the rotor into models leads to full agreement with our experiments. (iii) Finally, in our third system, we study the behaviour of the granular Leidenfrost state. This is a particular state in which a denser region of grains is floating on top of a dilute one. We built a setup, which permits the observation of the granular Leidenfrost state for a wide range of parameters and more specifically allows for thorough characterization of the low-frequency oscillation that is present in this state. In this experiment, unlike the others two, we do not introduce an external object, since the intruder is generated by the system itself.
Original languageEnglish
Awarding Institution
  • University of Twente
Supervisors/Advisors
  • van der Meer, Devaraj, Supervisor
Award date27 Jan 2017
Place of PublicationEnschede
Publisher
Print ISBNs978-90-365-4295-1
DOIs
Publication statusPublished - 27 Jan 2017

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rotors
ethyl alcohol
dunes
corn
collision rates
wheat
shear thinning
theses
fluids
granular materials
paints
settling
angular velocity
asteroids
rheology
medicine
food
avalanches
floating
water

Keywords

  • IR-102821
  • METIS-320194

Cite this

Oyarte Galvez, Loreto Alejandra. / Anomalous intruder response in diverse granular systems. Enschede : Universiteit Twente, 2017. 136 p.
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title = "Anomalous intruder response in diverse granular systems",
abstract = "The definition of granular matter is extremely broad; any collection of conglomeration of particles larger than 100 micrometers can be considered as part of this group, and virtually the entire universe is composed of them. Examples are found in many fields, e.g. in nature (dunes, avalanches, asteroids, etc.), industry (preparation of medicines, manufacture of concretes, paints, etc.), and even food (corn, wheat, etc.). As a result, its applications are very varied and numerous, and undoubtedly constitute an important focus of study for scientists. In this thesis, we attempted to understand and describe granular materials probing three distinct granular systems with an intruder. (i) In our first system, we study the impact and settling of a sphere in a suspension of cornstarch in which the suspending fluid is gradually changed from pure water to pure ethanol. We show that partly replacing water by ethanol strongly alters the suspension rheology, turning the suspension from a strongly shear-thickening fluid into its opposite: a shear-thinning liquid. We relate the macroscopic behaviour to the microscopic details of the grain-grain interaction using atomic force microscopy. (ii) In our second system, we build a rotor similar to the famous Smoluchowski-Feynman device, which is immersed in a granular gas and experimentally study the behaviour of its angular velocity distribution. We find that the existing models are not capable of adequately describing the experimentally observed distribution. However, we show that incorporating the effects of the external friction and the collision rate experienced by the rotor into models leads to full agreement with our experiments. (iii) Finally, in our third system, we study the behaviour of the granular Leidenfrost state. This is a particular state in which a denser region of grains is floating on top of a dilute one. We built a setup, which permits the observation of the granular Leidenfrost state for a wide range of parameters and more specifically allows for thorough characterization of the low-frequency oscillation that is present in this state. In this experiment, unlike the others two, we do not introduce an external object, since the intruder is generated by the system itself.",
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Anomalous intruder response in diverse granular systems. / Oyarte Galvez, Loreto Alejandra.

Enschede : Universiteit Twente, 2017. 136 p.

Research output: ThesisPhD Thesis - Research UT, graduation UTAcademic

TY - THES

T1 - Anomalous intruder response in diverse granular systems

AU - Oyarte Galvez, Loreto Alejandra

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N2 - The definition of granular matter is extremely broad; any collection of conglomeration of particles larger than 100 micrometers can be considered as part of this group, and virtually the entire universe is composed of them. Examples are found in many fields, e.g. in nature (dunes, avalanches, asteroids, etc.), industry (preparation of medicines, manufacture of concretes, paints, etc.), and even food (corn, wheat, etc.). As a result, its applications are very varied and numerous, and undoubtedly constitute an important focus of study for scientists. In this thesis, we attempted to understand and describe granular materials probing three distinct granular systems with an intruder. (i) In our first system, we study the impact and settling of a sphere in a suspension of cornstarch in which the suspending fluid is gradually changed from pure water to pure ethanol. We show that partly replacing water by ethanol strongly alters the suspension rheology, turning the suspension from a strongly shear-thickening fluid into its opposite: a shear-thinning liquid. We relate the macroscopic behaviour to the microscopic details of the grain-grain interaction using atomic force microscopy. (ii) In our second system, we build a rotor similar to the famous Smoluchowski-Feynman device, which is immersed in a granular gas and experimentally study the behaviour of its angular velocity distribution. We find that the existing models are not capable of adequately describing the experimentally observed distribution. However, we show that incorporating the effects of the external friction and the collision rate experienced by the rotor into models leads to full agreement with our experiments. (iii) Finally, in our third system, we study the behaviour of the granular Leidenfrost state. This is a particular state in which a denser region of grains is floating on top of a dilute one. We built a setup, which permits the observation of the granular Leidenfrost state for a wide range of parameters and more specifically allows for thorough characterization of the low-frequency oscillation that is present in this state. In this experiment, unlike the others two, we do not introduce an external object, since the intruder is generated by the system itself.

AB - The definition of granular matter is extremely broad; any collection of conglomeration of particles larger than 100 micrometers can be considered as part of this group, and virtually the entire universe is composed of them. Examples are found in many fields, e.g. in nature (dunes, avalanches, asteroids, etc.), industry (preparation of medicines, manufacture of concretes, paints, etc.), and even food (corn, wheat, etc.). As a result, its applications are very varied and numerous, and undoubtedly constitute an important focus of study for scientists. In this thesis, we attempted to understand and describe granular materials probing three distinct granular systems with an intruder. (i) In our first system, we study the impact and settling of a sphere in a suspension of cornstarch in which the suspending fluid is gradually changed from pure water to pure ethanol. We show that partly replacing water by ethanol strongly alters the suspension rheology, turning the suspension from a strongly shear-thickening fluid into its opposite: a shear-thinning liquid. We relate the macroscopic behaviour to the microscopic details of the grain-grain interaction using atomic force microscopy. (ii) In our second system, we build a rotor similar to the famous Smoluchowski-Feynman device, which is immersed in a granular gas and experimentally study the behaviour of its angular velocity distribution. We find that the existing models are not capable of adequately describing the experimentally observed distribution. However, we show that incorporating the effects of the external friction and the collision rate experienced by the rotor into models leads to full agreement with our experiments. (iii) Finally, in our third system, we study the behaviour of the granular Leidenfrost state. This is a particular state in which a denser region of grains is floating on top of a dilute one. We built a setup, which permits the observation of the granular Leidenfrost state for a wide range of parameters and more specifically allows for thorough characterization of the low-frequency oscillation that is present in this state. In this experiment, unlike the others two, we do not introduce an external object, since the intruder is generated by the system itself.

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KW - METIS-320194

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DO - 10.3990/1.9789036542951

M3 - PhD Thesis - Research UT, graduation UT

SN - 978-90-365-4295-1

PB - Universiteit Twente

CY - Enschede

ER -

Oyarte Galvez LA. Anomalous intruder response in diverse granular systems. Enschede: Universiteit Twente, 2017. 136 p. https://doi.org/10.3990/1.9789036542951