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Item Model-based inquiry in the high school chemistry classroom: how does model-based inquiry affect learning retention?(Montana State University - Bozeman, College of Letters & Science, 2023) Carson, Christa Eleanor; Chairperson, Graduate Committee: C. John GravesModel-based inquiry is a style of pedagogy that involves the creation and analysis of physical, conceptual, and mathematical models as a means of teaching and learning science. This study aimed to ascertain the capacity of model-based inquiry (MBI) to impact learning retention in students of a 9th and 10th-grade chemistry course. Over the course of two introductory chemistry units, students used MBI-styled activities and unit storylines to uncover essential ideas. The fundamental concepts of each unit were assessed using a pre-test and post-test (Post I), with an additional post-test (Post II) administered several weeks after the culmination of that unit. Students were also prompted for their confidence level on these assessments. To analyze the interplay between MBI, attitudes about science, and comprehension, students were surveyed using the Colorado Learning Attitudes about Science Survey before and after the research period. Additionally, a sample of students was interviewed about their knowledge and experience using scientific models. Analysis of the quantitative and qualitative data from this study has revealed that a guided approach to MBI has some positive effect on learning retention. This study's use of MBI was found to have a moderate impact on student attitudes about learning chemistry, and a limited impact on student understanding of scientific modeling.Item Modeling in high school earth and space science(Montana State University - Bozeman, College of Letters & Science, 2021) Wise, Emily Sarah; Chairperson, Graduate Committee: Greg FrancisModeling is a key practice embedded in the Next Generation Science Standards (NGSS) and its purpose is to help students develop their ability to reason, explain, and apply their classroom learning to real world phenomena. Students often struggle to take their science content learning and use to explain complex scenarios. In this study, all teaching and learning was done via Zoom for the duration of the research period due the COVID-19 pandemic. In order to develop the skills required for modeling and to help promote engagement during synchronous class sessions, students participated in twelve weeks of virtual modeling-based instruction and synchronous classroom activities as well as two summative assessments that required them to model complex phenomena around Earth and space science. Students were asked to self-evaluate their ability to use and develop models at the beginning and the end of the research period. The data did not show that student confidence improved from the beginning to the end of the treatment, nor did student scores on the summative modeling assessments improve from the beginning to the end. Required remote learning was a new experience for all students and it proved to be a tremendous struggle for both engagement and assignment completion and submission.Item Reduced-order aeroelastic modeling of a torsionally compliant UAV rotor blade(Montana State University - Bozeman, College of Engineering, 2021) Marks, Montana William; Chairperson, Graduate Committee: Mark JankauskiSmall-scale quadrotor helicopters, or quadcopters, have increased in popularity significantly in the past decade. These unmanned aerial vehicles (UAVs) have a wide range of applications - from aerial photography and cinematography to agriculture. Increasing flight time and payload capacity are of the utmost importance when designing these systems, and reducing vehicle weight is the simplest method for improving these performance metrics. However, lighter components and structures are often more flexible and may deform during operation. This is especially the case for flexible UAV blade rotor behavior during flight. Modeling rotor blade deformations is non-trivial due to the coupling between the structure and the surrounding flow, which is called Fluid-Structure Interaction (FSI). Several methods exist for FSI modeling where the most common involves integrating Finite Element and Computational Fluid Dynamics solvers. However, these higher-fidelity models are computationally expensive and are not ideal for parametric studies that consider variable rotor geometry, material properties or other physical characteristics. This research develops low-order modeling techniques that can be leveraged by UAV rotor designers. Here, a reduced-order FSI model of a small-scale UAV rotor blade is developed using Lagrangian mechanics paired with a blade element model. The rotor blade is discretized into rectangular elements along the span. Each blade element is constrained to uni-axial rotation about the span-wise axis and is treated as a torsional stiffness element. The quasi-static equilibrium state of the structure due to aerodynamic forces at user-defined operational conditions is then determined. The model presented is capable of producing a converged solution in as little as 0.016 seconds, as opposed to higher-order FSI models, which can take up to several orders of magnitude longer to solve. It is determined that the deflection of a flexible blade can reduce the total aerodynamic lift from 18-25% when compared to a rigid blade with the same initial geometry. It is shown that the model allows a user to tailor the initial pre-twist of the flexible rotor blade such that losses in lift are reduced to 0.68-5.7%.Item The design and testing of an axial condenser fan(Montana State University - Bozeman, College of Engineering, 2021) Kirk, David Michael; Chairperson, Graduate Committee: Kevin AmendeAxial or propeller fans are a subset of turbomachinery whose application is prevalent in everyday life. In the case of heating, ventilation, air conditioning, and refrigeration (HVAC&R), fans can be a large source of inefficient energy consumption due to their physical operating nature. With the global push for more efficient systems, components of HVAC&R equipment such as fans have become a focal point for researchers in academia and industry alike. Technological improvements in research equipment such as computational fluid dynamics (CFD) and additive manufacturing play a large role in achieving these improved efficiencies. The goal of this research is to improve the efficiency of an axial fan intended for cooling a micro-channel heat exchanger that is used in rooftop condenser units. A higher efficiency retrofit fan was iteratively designed using a commercial CFD software package, Star CCM+, which constitutes much of the research conducted in this project. The iterative models show that significant efficiency gains can be achieved through incremental alterations of classical fan blade geometry elements such as pitch, camber, skew, cross section loft path, chord length, thickness, etc. A physical model of the fan design thought to be the optimal choice for experimental analysis was 3D printed and tested using an AMCA Standard 210 setup. Upon analysis of the physical test results, several discrepancies between simulated and actual results were discovered, highlighting the importance of CFD model validation in the design process. Despite the efficiency gains and advancements in user-friendly packaged software, the simulation underpredicted the power demand and incorrectly depicted the fan's performance at critical operating points showing that improper usage of these experts' tools can inadvertently lead to developed solutions with significant error. While the designed fan achieves an improved peak static efficiency and volumetric flow rate of 53.9% and 4334 CFM respectively, it ultimately did not meet the operating parameters of the specific unit it was designed for and further improvements to the CFD model are needed.Item Cessna 182b windscreen material model development and full scale UAS to aircraft impact testing facility(Montana State University - Bozeman, College of Engineering, 2020) Arnold, Forrest Jacob; Chairperson, Graduate Committee: Douglas S. CairnsUnmanned Aircraft Systems (UAS) have become popular in the last decade. More than 1.5 million have been registered by the Federal Aviation Administration (FAA) since 2015. In order to understand the risk UAS pose to manned aircraft and make informed regulation decisions, the FAA has created air to air collision studies. As a part of the FAA general aviation air to air collision research, a Cessna 182 windscreen material model and a full scale impact testing facility were required. A Finite Element Crash Model of a Cessna 182 is in development as a part of the general aviation air to air collision research. The National Institute for Aviation Research at Wichita State University is managing development of the model. In support of that work, an LS-DYNA material model of the Poly(Methyl methacrylate) windscreen was developed. Results from tensile testing at multiple strain rates were used to develop material models using MAT_124 and MAT_187. A model of an impact tower was created to compare the material models to test results. The material models were tuned to better fit the impact tower test results. MAT_187 has more flexible material inputs, which allowed it to outperform MAT_124. A full scale impact testing facility was developed to support Finite Element model validation and direct testing of UAS to aircraft impact. A slingshot style launcher was designed and built to launch common quadcopter style UAS. Testing has shown that the launcher is capable of 120 knots with the accuracy required to repeatably hit the leading edge of a wing. Additionally, the launch site required a system for instrumented testing to compare experimental results with finite element results. A system was developed to allow flexible fixturing, impact speed and orientation measurement, and inclusion of load cells and strain gauges.Item Designing and assessing the effectiveness of Denil fishways using hydraulic modeling-based approaches(Montana State University - Bozeman, College of Engineering, 2019) Platt, Nolan Chalmers; Chairperson, Graduate Committee: Kathryn Plymesser; Matt Blank, Kathryn Plymesser, Kevin Kappenman and Joel Cahoon were co-authors of the article, 'Modeling upstream arctic grayling passage through Denil fishways in the Big Hole Valley, Montana' submitted to the journal 'The journal of ecohydraulics' which is contained within this thesis.; Matt Blank, Kathryn Plymesser, Kevin Kappenman and Joel Cahoon were co-authors of the article, 'Hydraulic design of a Denil fishway at pin-and-plank irrigation diversions: a technical report' submitted to the journal 'A technical report' which is contained within this thesis.Man-made, instream structures can pose barriers to fish movement. Fish move about river systems to reach habitats associated with various stages of their life histories. If access to required habitat is blocked, it can cause detrimental effects to fish populations. Removing barriers to fish movement is often socio-economically infeasible so fishways are used to promote fish passage around barriers. Denil fishways consist of a chute for water to flow through and baffles to slow water velocities; they are a relatively cheap solution for promoting upstream fish passage over low-head barriers. The Big Hole River basin is home to the last fluvial population of Arctic Grayling in the continental United States. Per an agreement between landowners and several government organizations, Denil fishways were installed at irrigation diversions in the Big Hole Valley to provide fish volitional routes to navigate irrigation diversions. Eleven Denil fishways at irrigation diversions were evaluated for their effectiveness at passing grayling by using hydraulic modeling techniques coupled with biologic data. Hydrologic data was applied to hydraulic models to estimate water surface elevations about the Denils over time. A passage index was developed which inferred passage efficiency of the fishway based on depths at the upstream and downstream ends and assigning a 'passage condition.' Passage windows were developed which describe times when the fishways functioned to 'allow', 'limit', or 'prevent' upstream passage. Across all sites fishways were predicted to 'allow' passage 6.4% of the time, 'limit' passage 17.2% of the time, and 'prevent' passage 10.3% of the time. The modelled depth combination at fishways was 'out of range' of the passage index 66.1% of the time. A hydraulic design process was proposed with the goal of designing Denil fishways at pin-and-plank irrigation diversions to promote upstream passage at low flows. Design criteria were established, explained, and presented. One-dimensional hydraulic modeling techniques for diversions and fishways was presented and used to determine design parameter values that optimize fish passage efficiency over a broad range of instream flows. We attempted to develop a novel method of assessing Denil structures using hydraulic models; our method is useful to managers because the effectiveness of fishways was assessed by considering how they functioned over a range of instream flows and at times associated with fish movement.Item The effect of model-based inquiry teaching on student engagement, and the NGSS science practices in high school biology(Montana State University - Bozeman, College of Letters & Science, 2017) Van Loo, Brennan J.; Chairperson, Graduate Committee: Walter WoolbaughThe Next Generation Science Standards (NGSS) have raised the bar of science education for teachers and students. The three stranded format of Disciplinary Core Ideas, Crosscutting Concepts, and Science Practices will require students to think and engage more deeply in the process of science. Achieving these rigorous standards for all students will require a greater level of motivation and engagement than I currently have in my classes. The purpose of this study is to investigate how model-based inquiry teaching, based on the framework of Ambitious Science Teaching, increases student motivation and engagement as well as how this framework improves student skills with the NGSS science practices. A model-based inquiry approach to science teaching emphasizes the skills and practices of scientists. During the treatment, students made an initial model to try to explain a scientific phenomenon. Classroom discourse and experiences formed the foundation of instruction, which was then used by students to revise their models. Data was collected through student surveys, and direct observations of student engagement and classroom discourse. Additionally, data was collected on students' ability to support a claim with evidence and reasoning. The results show that the treatment promoted engagement and that student skills in discourse and argumentation increased. However, students' perception of their motivation and engagement did not change with continued treatment. This study shows that model-based inquiry has significant value for students who have historic academic struggles as it moves science beyond the rote memorization that they struggle with, to explaining what is happening based on experimental evidence and personal experience.Item Acoustic propagation modeling for marine hydrokinetic applications(Montana State University - Bozeman, College of Engineering, 2016) Johnson, Charles Nathan; Chairperson, Graduate Committee: Erick JohnsonThe combination of riverine, tidal, and wave energy have the potential to supply over one third of the United States' annual electricity demand [1]. However, in order to deploy and test prototypes and commercial installations, marine hydrokinetic (MHK) devices must meet strict regulatory guidelines. These regulations mandate the maximum amount of noise that can be generated and sets particular thresholds for determining disturbance and injury caused by noise. In the absence of measured levels from in-situ deployments, a model for predicting the propagation of a MHK source in a real hydroacoustic environment needs to be established. An accurate model for predicting the propagation of a MHK source(s) in a real-life hydro-acoustic environment has been established. This model will help promote the growth and viability of marine, water, and hydrokinetic energy by confidently assuring federal regulations are meet and harmful impacts to marine fish and wildlife are minimal. A 3D finite-difference solution to the governing velocity-pressure equations is presented and offers advantages over other acoustic propagation techniques for MHK applications as spatially varying sound speeds, bathymetry, and bed composition that form complex 3D interactions can be modeled. This solution method also allows for the inclusion of complex MHK sound spectra from turbines and/or arrays of turbines. A number of different cases for hydro-acoustic environments have been validated by both analytical and numerical results from canonical and benchmark problems. Several of these key validation cases are presented in order to show the applicability and viability of a finite difference numerical implementation code for predicting acoustic propagation in a hydro environment. With the model successfully validated for hydro-acoustic environments, more complex and realistic MHK sources from turbines and/or arrays can be modeled. A systematic investigation of MHK relevant scenarios is presented with increasing complexity including a single- and multi- source investigation, a random phase change study, and a hydro-acoustic model integrationItem Surface hoar observations at the scale of a helicopter skiing operation(Montana State University - Bozeman, College of Letters & Science, 2014) Borish, Matthew John; Chairperson, Graduate Committee: Stephan G. CusterUnderstanding what controls coarse scale snowpack properties, such as surface hoar distribution, is imperative for predicting snow avalanches. Due in part to the inherent difficulties of winter travel in mountainous terrain, most spatial variability investigations of snow properties have been limited to relatively fine scales. To quantify snow surface spatial variability at the basin, region, and mountain range scales, a team of heli-skiing guides recorded observations describing surface hoar presence or absence coordinates, crystal size, and elevation throughout four major surface hoar formation periods over two heli-skiing seasons in rugged alpine terrain near Haines, Alaska across an extent of nearly 60 km. Geostatistical analysis yielded spherical semivariogram autocorrelation ranges from approximately 3-25 km, which is similar in size to many of the basins and regions within the study area. Kriging models built from the semivariograms were produced to aid geographic visualization of coarse scale snowpack processes. Geographically Weighted Regression revealed a positive relationship between elevation and surface hoar crystal size with adjusted R 2 values averaging near 0.40. The results of this research suggest it may be possible to identify areas with greater surface hoar growth and persistence potentials as a consequence of synoptic onshore or offshore flow, and glacially influenced katabatic winds. Additionally, larger surface hoar crystals may be found in the higher elevation avalanche starting zones in the alpine glaciated terrain near Haines, Alaska. These results can help in future efforts to forecast snow stability patterns over large areas.Item Normal mode visualization(Montana State University - Bozeman, College of Engineering, 1992) Reddy, Madhusudhan Y.