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- All Subjects: Particles
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Description
The Basilisk lizard is known for its agile locomotion capabilities on granular and aquatic media making it an impressive model organism for studying multi-terrain locomotion mechanics. The work presented here is aimed at understanding locomotion characteristics of Basilisk lizards through a systematic series of robotic and animal experiments. In this work, a Basilisk lizard inspired legged robot with bipedal and quadrupedal locomotion capabilities is presented. A series of robot experiments are conducted on dry and wet (saturated) granular media to determine the effects of gait parameters and substrate saturation, on robot velocity and energetics. Gait parameters studied here are stride frequency and stride length. Results of robot experiments are compared with previously obtained animal data. It is observed that for a fixed robot stride frequency, velocity and stride length increase with increasing saturation, confirming the locomotion characteristics of the Basilisk lizard. It is further observed that with increasing saturation level, robot cost of transport decreases. An identical series of robot experiments are performed with quadrupedal gait to determine effects of gait parameters on robot performance. Generally, energetics of bipedal running is observed to be higher than quadrupedal operation. Experimental results also reveal how gait parameters can be varied to achieve different desired velocities depending on the substrate saturation level. In addition to robot experiments on granular media, a series of animal experiments are conducted to determine and characterize strategies
exhibited by Basilisk lizards when transitioning from granular to aquatic media.
exhibited by Basilisk lizards when transitioning from granular to aquatic media.
ContributorsJayanetti, Vidu (Author) / Marvi, Hamid (Thesis advisor) / Emady, Heather (Committee member) / Lee, Hyunglae (Committee member) / Arizona State University (Publisher)
Created2018
Description
Characterization of particulate process and product design is a difficult field because of the unique bulk properties and behaviors of particles that differ from gasses and liquids. The purpose of this research is to develop an equation to relate the angle of repose and flowability, the ability of the particle to flow as it pertains to particulate processes and product design. This research is important in multiple industries such as pharmaceuticals and food processes.
ContributorsNugent, Emily Rose (Author) / Emady, Heather (Thesis director) / Marvi, Hamidreza (Committee member) / Materials Science and Engineering Program (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This thesis investigates the effects of differing diameters, removal of antistatic forces, and varying moisture content on the shear stress properties of granular glass beads through use of a Freeman FT4 Powder Rheometer. A yield locus results from plotting the experimental shear stress values (kPa) vs. the applied normal stress value (kPa). From these yield loci, Mohr’s Circles are constructed to quantitatively describe flowability of tested materials in terms of a flow function parameter.
By testing 120-180 µm, 120-350 µm, 250-350 µm, and 430-600 µm dry glass bead ranges, an increase in diameter size is seen to result in both higher shear stress values and an increasing slope of plotted shear stress vs. applied normal stress. From constructed Mohr’s Circles, it is observed that flow function is quite high amongst tested dry materials, all yielding values above 20. A high flow function value (>10) is indicative of a good flow.1 Flow function was observed to increase with increasing diameter size until a slight drop was observed at the 430-600 µm range, possibly due to material quality or being near the size limitation of testing within the FT4, where materials must be less than 1000 µm in diameter.However, no trend could be observed in flowability as diameter size was increased.
Through the use of an antistatic solution, the effect of electrostatic forces generated by colliding particles was tested. No significant effect on the shear stress properties was observed.
Wet material testing occurred with the 120-180 µm glass bead range using a deionized water content of 0%, 1%, 5%, 15%, and 20% by mass. The results of such testing yielded an increase in shear stress values at applied normal stress values as moisture content is increased, as well as a decrease in the resulting flow function parameter. However, this trend changed as 20% moisture content was achieved; the wet material became a consistent paste, and a large drop in shear stress values occurred along with an increase in flowability.
By testing 120-180 µm, 120-350 µm, 250-350 µm, and 430-600 µm dry glass bead ranges, an increase in diameter size is seen to result in both higher shear stress values and an increasing slope of plotted shear stress vs. applied normal stress. From constructed Mohr’s Circles, it is observed that flow function is quite high amongst tested dry materials, all yielding values above 20. A high flow function value (>10) is indicative of a good flow.1 Flow function was observed to increase with increasing diameter size until a slight drop was observed at the 430-600 µm range, possibly due to material quality or being near the size limitation of testing within the FT4, where materials must be less than 1000 µm in diameter.However, no trend could be observed in flowability as diameter size was increased.
Through the use of an antistatic solution, the effect of electrostatic forces generated by colliding particles was tested. No significant effect on the shear stress properties was observed.
Wet material testing occurred with the 120-180 µm glass bead range using a deionized water content of 0%, 1%, 5%, 15%, and 20% by mass. The results of such testing yielded an increase in shear stress values at applied normal stress values as moisture content is increased, as well as a decrease in the resulting flow function parameter. However, this trend changed as 20% moisture content was achieved; the wet material became a consistent paste, and a large drop in shear stress values occurred along with an increase in flowability.
ContributorsKleppe, Cameron Nicholas (Author) / Emady, Heather (Thesis director) / Vajrala, Spandana (Committee member) / Chemical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
Pseudo-steady state (PSS) flow is an important time-dependent flow regime that
quickly follows the initial transient flow regime in the constant-rate production of
a closed boundary hydrocarbon reservoir. The characterization of the PSS flow
regime is of importance in describing the reservoir pressure distribution as well as the
productivity index (PI) of the flow regime. The PI describes the production potential
of the well and is often used in fracture optimization and production-rate decline
analysis. In 2016, Chen determined the exact analytical solution for PSS flow of a
fully penetrated vertically fractured well with finite fracture conductivity for reservoirs
of elliptical shape. The present work aimed to expand Chen’s exact analytical solution
to commonly encountered reservoirs geometries including rectangular, rhomboid,
and triangular by introducing respective shape factors generated from extensive
computational modeling studies based on an identical drainage area assumption. The
aforementioned shape factors were generated and characterized as functions for use
in spreadsheet calculations as well as graphical format for simplistic in-field look-up
use. Demonstrative use of the shape factors for over 20 additional simulations showed
high fidelity of the shape factor to accurately predict (mean average percentage error
remained under 1.5 %) the true PSS constant by modulating Chen’s solution for
elliptical reservoirs. The methodology of the shape factor generation lays the ground
work for more extensive and specific shape factors to be generated for cases such as
non-concentric wells and other geometries not studied.
quickly follows the initial transient flow regime in the constant-rate production of
a closed boundary hydrocarbon reservoir. The characterization of the PSS flow
regime is of importance in describing the reservoir pressure distribution as well as the
productivity index (PI) of the flow regime. The PI describes the production potential
of the well and is often used in fracture optimization and production-rate decline
analysis. In 2016, Chen determined the exact analytical solution for PSS flow of a
fully penetrated vertically fractured well with finite fracture conductivity for reservoirs
of elliptical shape. The present work aimed to expand Chen’s exact analytical solution
to commonly encountered reservoirs geometries including rectangular, rhomboid,
and triangular by introducing respective shape factors generated from extensive
computational modeling studies based on an identical drainage area assumption. The
aforementioned shape factors were generated and characterized as functions for use
in spreadsheet calculations as well as graphical format for simplistic in-field look-up
use. Demonstrative use of the shape factors for over 20 additional simulations showed
high fidelity of the shape factor to accurately predict (mean average percentage error
remained under 1.5 %) the true PSS constant by modulating Chen’s solution for
elliptical reservoirs. The methodology of the shape factor generation lays the ground
work for more extensive and specific shape factors to be generated for cases such as
non-concentric wells and other geometries not studied.
ContributorsSharma, Ankush, M.S (Author) / Chen, Kang Ping (Thesis advisor) / Green, Matthew D (Thesis advisor) / Emady, Heather (Committee member) / Arizona State University (Publisher)
Created2017
Description
Rotary drums are used to manufacture pharmaceuticals, cement, food, and other particulate products because of their high heat and mass transfer rates. These processes are governed by particle parameters, such as particle size, particle distribution, and shape, and operating parameters, such as rotation rate and fill level. Enormous energy savings are possible with further research in rotary drums due to potential increases in operating efficiency. This study investigates the drum rotation rate on particle bed temperature at temperatures above 500 °C to see the role that radiation heat transfer plays in this process. 2 mm silica beads and a stainless steel rotary drum were used at a fill level of 25% with rotation rates from 2-10 rpm. A new setup and procedure were developed using heating coils and an IR camera to reach high temperatures. The inner drum wall temperature exceeded the outer drum wall temperature because the steel transmitted more heat into the drum at higher temperatures. Although it was unclear whether the heat transfer rate was affected by the increasing rotation rate, the highest final average particle temperature was obtained at 5 rpm. The particle bed temperature distribution narrowed as the rotation rate increased because, at higher rotation rates, more particles are in contact with the drum wall than at lower rotation rates.
ContributorsTronstad, Joel (Author) / Emady, Heather (Thesis director) / Holloway, Julianne (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor) / Dean, W.P. Carey School of Business (Contributor)
Created2023-05
Description
The current research is based on the principles of three-dimensional discrete element method (3D – DEM) through simulations, by using heat transfer models in EDEM, to investigate the effects of fill level, rotation rate and particle size on the steady-state conduction heat transfer in rotary drums. The high heat and mass transfer rates obtained through rotary drums make them very useful for powder mixing and heating processes in metallurgical, cement, mining, pharmaceutical, detergent and other particulate processing applications. However, these complex processes are difficult to model and operate since the particles can have a wide range of properties, and there is currently no way to predict the optimal operating conditions for a given material.
Steady-state heat transfer by conduction forms the basis for understanding other steady-state and unsteady-state heat transfer in a rotary drum – conduction, convection and radiation. Statistical analysis is carried out to determine the effects of these process parameters and find optimal operating conditions, which will thereby improve the heat transfer efficiency in rotary drums. A stainless-steel drum with a diameter of 6 inches and a length of 3 inches was modeled in EDEM with silica beads of sizes 2 mm, 3 mm and 4 mm at fill levels of 10%, 17.5% and 25%, and at rotation rates of 2 rpm, 5 rpm and 10 rpm. It was found that the heating uniformity increased with decreasing particle size, decreasing fill level and increasing rotation rate. This research is the first step towards studying the other heat transfer modes and various other process parameters. Better understanding of the various heat transfer modes, when used in combination for heating the particles, will be beneficial in improving the operating efficiency, reducing material costs and leading to significant energy conservation on a global scale.
Steady-state heat transfer by conduction forms the basis for understanding other steady-state and unsteady-state heat transfer in a rotary drum – conduction, convection and radiation. Statistical analysis is carried out to determine the effects of these process parameters and find optimal operating conditions, which will thereby improve the heat transfer efficiency in rotary drums. A stainless-steel drum with a diameter of 6 inches and a length of 3 inches was modeled in EDEM with silica beads of sizes 2 mm, 3 mm and 4 mm at fill levels of 10%, 17.5% and 25%, and at rotation rates of 2 rpm, 5 rpm and 10 rpm. It was found that the heating uniformity increased with decreasing particle size, decreasing fill level and increasing rotation rate. This research is the first step towards studying the other heat transfer modes and various other process parameters. Better understanding of the various heat transfer modes, when used in combination for heating the particles, will be beneficial in improving the operating efficiency, reducing material costs and leading to significant energy conservation on a global scale.
ContributorsBheda, Bhaumik (Author) / Emady, Heather (Thesis advisor) / Muhich, Christopher (Committee member) / Nielsen, David (Committee member) / Arizona State University (Publisher)
Created2020
Description
As experiencing hot months and thermal stresses is becoming more common, chemically protective fabrics must adapt and provide protections while reducing the heat stress to the body. These concerns affect first responders, warfighters, and workers regularly surrounded by hazardous chemical agents. While adapting traditional garments with cooling devices provides one route to mitigate this issue, these cooling methods add bulk, are time limited, and may not be applicable in locations without logistical support. Here I take inspiration from nature to guide the development of smart fabrics that have high breathability, but self-seal on exposure to target chemical(s), providing a better balance between cooling and protection.
Natural barrier materials were explored as a guide, focusing specifically on prickly pear cacti. These cacti have a natural waxy barrier that provides protection from dehydration and physically changes shape to modify surface wettability and water vapor transport. The results of this study provided a basis for a shape changing polymer to be used to respond directly to hazardous chemicals, swelling to contain the agent.
To create a stimuli responsive material, a novel superabsorbent polymer was synthesized, based on acrylamide chemistry. The polymer was tested for swelling properties in a wide range of organic liquids and found to highly swell in moderately polar organic liquids. To help predict swelling in untested liquids, the swelling of multiple test liquids were compared with their thermodynamic properties to observe trends. As the smart fabric needs to remain breathable to allow evaporative cooling, while retaining functionality when soaked with sweat, absorption of water, as well as that of an absorbing liquid in the presence of water were tested.
Micron sized particles of the developed polymer were deposited on a plastic mesh with pore size and open area similar to common clothing fabric to establish the proof of concept of using a breathable barrier to provide chemical protection. The polymer coated mesh showed minimal additional resistance to water vapor transport, relative to the mesh alone, but blocked more than 99% of a xylene aerosol from penetrating the barrier.
Natural barrier materials were explored as a guide, focusing specifically on prickly pear cacti. These cacti have a natural waxy barrier that provides protection from dehydration and physically changes shape to modify surface wettability and water vapor transport. The results of this study provided a basis for a shape changing polymer to be used to respond directly to hazardous chemicals, swelling to contain the agent.
To create a stimuli responsive material, a novel superabsorbent polymer was synthesized, based on acrylamide chemistry. The polymer was tested for swelling properties in a wide range of organic liquids and found to highly swell in moderately polar organic liquids. To help predict swelling in untested liquids, the swelling of multiple test liquids were compared with their thermodynamic properties to observe trends. As the smart fabric needs to remain breathable to allow evaporative cooling, while retaining functionality when soaked with sweat, absorption of water, as well as that of an absorbing liquid in the presence of water were tested.
Micron sized particles of the developed polymer were deposited on a plastic mesh with pore size and open area similar to common clothing fabric to establish the proof of concept of using a breathable barrier to provide chemical protection. The polymer coated mesh showed minimal additional resistance to water vapor transport, relative to the mesh alone, but blocked more than 99% of a xylene aerosol from penetrating the barrier.
ContributorsManning, Kenneth (Author) / Rykaczewski, Konrad (Thesis advisor) / Burgin, Timothy (Committee member) / Emady, Heather (Committee member) / Green, Matthew (Committee member) / Thomas, Marylaura (Committee member) / Arizona State University (Publisher)
Created2020
Description
Regolith excavation systems are the enabling technology that must be developed in order to implement many of the plans for in-situ resource utilization (ISRU) that have been developed in recent years to aid in creating a lasting human presence on the surface of the Moon, Mars, and other celestial bodies. The majority of proposed ISRU excavation systems are integrated onto a wheeled mobility system, however none yet have proposed the use of a screw-propelled vehicle, which has the potential to augment and enhance the capabilities of the excavation system. As a result, CASPER, a novel screw-propelled excavation rover is developed and analyzed to determine its effectiveness as a ISRU excavation system. The excavation rate, power, velocity, cost of transport, and a new parameter, excavation transport rate, are analyzed for various configurations of the vehicle through mobility and excavation tests performed in silica sand. The optimal configuration yielded a 28.4 kg/hr excavation rate and11.2 m/min traverse rate with an overall system mass of 3.4 kg and power draw of26.3 W. CASPER’s mobility and excavation performance results are compared to four notable proposed ISRU excavation systems of various types. The results indicate that this architecture shows promise as an ISRU excavator because it provides significant excavation capability with low mass and power requirements.
ContributorsGreen, Marko (Author) / Marvi, Hamid (Thesis advisor) / Emady, Heather (Committee member) / Lee, Hyunglae (Committee member) / Arizona State University (Publisher)
Created2021