Deployable structures have made an immense impact in the engineering world. The concept of the deployable structure has been able to reduce costs and sizing limits across a variety of use cases. However, sizing and cost reduction are not the only reasons that deployable structures are prominent. There are unique propeller blades that have entered into the world of deployable structures, where the ability to be stowed away and deployed to a much larger diameter can increase launch flexibility, and the engine efficiencies of aircraft. Although, most of the deployable propeller blades that have been designed in studies have the usual hinge mechanism where the down side of a hinge is that it does not necessarily provide any stiffness nor does it change the diameter of the propeller blade when stowed away. However, an unique strategy, that uses the underlying principle of snap through buckling can help to negate the use of hinges. This principle allows the propeller blade itself to be folded and stowed away, where stored strain energy is used in order to self-deploy back into the original shape. This paper will present an overall approach to the structural architecture development, conceptual prototype fabrication, and computational analysis of a foldable propeller blade.

Lightweight aerospace structures have been sought after since humans took flight in 1903, making major strides in NASA's pursuit of the moon with the development of sandwich panel composites. Sandwich structures typically consist of two stiff phases (i.e., face sheets) separated by a lightweight phase (i.e., core), which are stacked together through adhesive layers. Such a structural arrangement provides a high stiffness-to-weight ratio and is often used in applications where weight saving is critical. Functionally Graded Materials (FGMs), refer to multifunctional materials, which contain a spatial variation of composition and/or microstructure for the specific purpose of altering thermal and structural properties. Recent advancements in Additive Manufacturing (AM), or 3D printing, drastically increased research capabilities. This thesis poses two novel concepts. First, sandwich beams manufactured as a single unit through additive manufacturing, eliminates the need for secondary bonding used in traditional sandwich structures. Second, with the introduction of a Functionally Graded (FG) core, sandwich structures offer enhanced flexural stiffness-to-weight ratio. To test these hypotheses, the design space of sandwich beams with FG cores is analytically explored by forming governing equations from existing methods and developing specific FG performance parameters. These equations are then exploited in MATLAB to map variation of the sandwich beam stiffness-to-weight ratio as a function of core relative density. Analytical estimations are verified for a particular design point of variable core density using the Finite Element (FE) models developed in the commercial FE program ABAQUS. Both the analytical and numerical results reveal a performance increase of approximately 31% of the stiffness-to-weight ratio for a variable core density. Finally, the selected design is additively manufactured using a poly-jet printer (Stratasys J55). The flexural modulus and strength of the additively manufactured sandwich beams are measured by the three-point bend test method. The experimental results clearly match the analytical and numerical estimations.

This study investigated the application of a polyelectrolyte (PE)-assisted metallic iron nanoparticle-integrated forward osmosis (FO) membrane to treat synthetic spacecraft wastewater comprising urea, ammonium carbonate, and linear alkylbenzene sulfonate (LAS). The draw solution (MgSO4) diluted via the FO operation was further treated using a nanofiltration (NF) membrane aimed at producing potable quality water by the FO-NF hybrid process. A cellulose triacetate FO membrane was functionalized by layer-by-layer deposition of polyallylamine hydrochloride (PAH) and polyacrylic acid (PAA) followed by incorporating zero valent iron nanoparticles (ZVINP) within the "bilayers". It required 14 bilayers to ensure a uniform coating as demonstrated via scanning electron microscopy image examination. The PE modification of the FO membrane counteracted the effects of membrane fouling and internal concentration polarization. Although the modified membrane appeared to accumulate slightly more foulants than the unmodified membrane, the modified membrane demonstrated higher water flux. After 10 hours of the FO operation, the water flux of the unmodified membrane observed a decreased while the modified membranes FS remained constant throughout. The reverse salt flux of the unmodified membrane was higher than the functionalized membrane. The RSF of the unmodified membrane increased while the modified membranes results remained constant throughout the process. The higher water flux of the functionalized membrane can be attributed to the deposition of PE-ZVINP that may have reduced the effects of ICP and RSF. The performance of the FO-NF hybrid process was evaluated by comparing the removal of nitrogen (TN) and total organic carbon (TOC) from the wastewater using a bench-scale setup. When using the modified FO membrane, the system removed 85.6% of TN and 86.2% TOC. This hybrid FO-NF system is expected to reduce the overall energy input and membrane operation cost when treating various wastewaters including the spacecraft wastewater.

The objective of this study is to refine the understanding of micro-fluidics subject to micro-gravity in an attempt to support future space exploration efforts. A combination of experimental and numerical approaches were utilized to build a validated assessment approach. A quasi-pore geometry, inspired by CT scans of rat bones, was used in lieu of human bone structures. A quasi-1D assessment of the conservation of momentum was used to identify the dominant forces acting on the fluid at the operating length-scales. The dominant forces were surface tension, gravity, and shear stress. Experiments were conducted to visualize the flow moving through the quasi-pore geometry. Computational Fluid Dynamics (CFD) was used to create a corresponding model of the experiments in order to illicit further insight. The CFD models were validated by using micro-fluidic experiments. Once validated, the CFD model was also used to study micro-fluids in micro-gravity conditions. The results showed that gravity has a significant effect on the flow pattern of fluids through micro-fluidic porous features. The results can be correlated to the fluid flow through bone pores on Earth versus in micro-gravity. This suggests that interstitial fluid flow is influenced by the effects of micro-gravity leading to physiological changes in astronaut bones.

With the use deployable drones becoming more common research into their improvement is necessary. Deployable drones that are launched from tubes have size limits on the diameter of the propeller during launch and storage. The purpose of this research is to develop deployable propeller blades for practical uses, such as tube launched propeller driven drones and easier to transport wind turbine blades. A deployable propeller will allow for the utilization of larger propellers when a large non-deployable blade isn't an option. Because deployable propellers need to fold, the deployable propeller blades were designed to be hollow and with a slit across the leading and trailing edges of the blades. Because of this unique design, a deployable propeller is not as structurally sound as a conventional propeller, and it requires pressure distributions to be sure the propeller can withstand operation without becoming deformed and compromised. My work will focus on using Computational Fluid Dynamics (CFD) modeling and physical testing to test the aerodynamic design concerns of the deployable propeller, the effects of the unique design requirements on its aerodynamics, and developing a model to quantify the aerodynamic drivers of the deployable propeller. The results indicated that the modifications used to make the propeller deployable did not prevent the propeller from functioning properly and that the model was accurate enough to be used as a method for testing potential designs before manufacturing and physically testing prototypes.

This currently presented work is an evaluation of the characteristics of different cooling hole geometries to particulate ingestion clogging. Experimentation was conducted using a premixed bluff body flame combustor facility to generate high temperature combustor flow conditions. Sand ingestion along the cooling path of the combustion liner was reproduced using an air-assisted seeder providing consistent sand ingestion. Mass flow rate of cooling air was controlled using a sonic orifice downstream of a pressure regulator so that the mass flow rate of the air and sand mixture is independent of the clogging state. Pressure data upstream of a small section of a combustion liner was recorded to quantify the clogging of the different combustion liner cooling geometries over time. Several geometries were tested including 3 "S" shaped slots with varying width and length, along with tapered straight slots, and compared to the traditional straight round hole. It was found that a diverging orientation of the tapered slot had the most promising performance mitigating particulate deposition. The displacement boundary layer growth interaction with the main flow within the diverging section of the slot is discussed as the main contributing factor to resist clogging. The use of such a clogging-resistant combustion liner could drastically reduce the maintenance necessary for vehicles operating in sandy and dusty environments, reducing the overall operational cost, and lowering risks of complete failure of the aircraft propulsion system.

This multidisciplinary study provides a comprehensive visualization of airborne aerosols and droplets coming into contact with a crossflow of moving air utilizing both experimental particle measuring methods and multiphase computational fluids dynamics (CFD). The aim of this research is to provide a Eulerian visualization of how ventilation can alter the position and density of an aerosol cloud, with the goal of applying this information to our understanding of social distancing ranges within outdoor settings and ventilated rooms. The results indicate that even minor perpendicular crossflows across the trajectory of an aerosol cloud can greatly reduce both the linear displacement and density of the cloud, with negligible increases in density along the flow path.

Aerodynamic optimization is a key step in designing planes, cars, and even buildings. Numerical modeling is used to automate the optimization process and can use different methods to iterate through designs. In this process, consideration of the starting design is paramount as a poor choice can use up computational time and effort. Often, these designs are made with the intention of being out in the open, for which studies on shape variations in freestream situations abound. However, for the case where an object must be placed in the wake of another, there is little research. The study presented here aims to help fill this gap, starting with a case of an elliptical fairing design placed around a cylinder in the wake of a D shaped tube. The fairing itself is parameterized to gain an understanding of how its shape and relative location to the D-tube influence both the fairing itself and the D-tube. The evaluations are done using numerical models that are both validated and measured for uncertainty. Following that, the results are used to provide an initial fairing design for a real case, that being of an instrument on NASA's Dragonfly drone. The example is also used to provide a brief comparison to the trends seen in the 2D characterization as compared to trends seen in freestream design. In total, this research aims to provide a starting point for understanding how design choices affect the aerodynamics of a fairing in a bluff body wake.

Beyond the protective confines of Earth's atmosphere and magnetosphere, spacecraft are subject to constant bombardment by high-energy charged particles originating from our Sun in the form of Solar Particle Events (SPEs), and from outside the solar system in the form of Galactic Cosmic Rays (GCRs). The harm these particles do can be reduced or mitigated outright through radiation shielding. Because protons and other charged particles comprise most of these radiation particles, strong magnetic fields could be generated around spacecraft to deflect incoming charged radiation particles. This thesis investigates the performance of specific configurations of toroidal superconducting solenoids to generate magnetic fields that deflect incoming energetic protons via the Lorentz force. Bulk material shielding configurations using various thicknesses of liquid water are similarly investigated, as are combination shielding configurations combining the best-performing toroidal shielding configurations with a small bulk material shield surrounding the spacecraft. The water shielding configurations tested included shields of uniform thicknesses from 1 cm to 10 cm surrounding an Apollo CSM-sized cylindrical candidate spacecraft. Water shielding was found to be very effective at reducing the SPE dose, from a 86\% reduction at 1 cm of water to a 94\% reduction at 10 cm. However water shielding was found to be minimally effective against the much higher energy Galactic Cosmic Ray protons, with no dose reduction at 1 cm and a paltry 1\% reduction at 10 cm. The toroidal shielding geometric configurations tested consisted of either 5 or 10 primary toroidal shields surrounding the candidate spacecraft, as was the addition of smaller nested toroidal shields inside the primary toroids and of toroids on the spacecraft's endcaps. The magnetic field strengths tested were 1.7 Tesla, 8.5 Tesla, and 17 Tesla. The best geometric configurations of electrodynamic shielding consisted of 5 primary toroidal shields, 5 total nested shields placed inside the primary toroids, and 2 total shields on the spacecraft's endcaps. The second best geometric configuration consisted of 10 primary toroidal shields plus two total endcap shields. These configurations at 1.7 Tesla reduced the SPE dose by 87\% and 87\%, and reduced the GCR dose by 11\% and 10\%. At 17 Tesla, these configurations both reduced the SPE dose by 90\%, and reduced the GCR dose by 76\% and 61\%. Combining these two configurations with a 1 cm-thick shield of water improved performance against SPE protons to 95\% and 93\% at 1.7 Tesla, and a 97\% and 96\% reduction at 17 Tesla. GCR dose reductions decreased slightly. Passive material shielding was found capable of providing substantial protection against SPE protons, but was minimally effective against GCR protons without very thick shielding. Electrodynamic shielding, at magnetic field strengths of 1.7 Tesla, was found to be similarly effective against SPE protons, and marginally more effective against GCR protons. Combining the best toroidal shielding configurations, at magnetic field strengths of 1.7 Tesla, with water shielding yielded high protection against SPE protons, but still marginal protection against GCR protons. Increasing the magnetic field strength to 17 Tesla was found to provide very high protection against SPE protons, and to significantly reduce the radiation dose from GCR protons. Of all shielding configurations tested, only those electrodynamic configurations with magnetic fields of 17 Tesla were able to reduce the GCR dose by more than half.

In order to enhance accessibility to microgravity research, the design process for experiments on the ISS must be streamlined and accessible to all scientific disciplines, not just aerospace engineers. Thus, a general design and analysis toolbox with accompanying best practices manual for microgravity liquid containment is proposed. The work presented in this thesis improves the design process by introducing a modular liquid tank design which can be filled, drained, or act as a passive liquid-gas separation device. It can also be pressurized, and used for aerosol spray. This tank can be modified to meet the design requirements of various experimental setups and liquids. Furthermore, rough simulations of this tank are presented and available to the user for modification. The simulation and design methodology for other general cases is discussed as well. After reading this thesis, the user should have a basic understanding of how liquids behave in microgravity. She will be able to run simple simulations, design, build, test, and fly a liquid management device which has been modified to suit the requirements of her specific experiment. The general tank design can be manufactured using 3-D printing, traditional CNC milling, or a combination thereof. The design methodology and best practices presented here have been used to design tanks used in experiments on the International Space Station for Budweiser and Lambda Vision. Both tanks functioned nominally on orbit. While the specific data from these experiments cannot be presented due to proprietary restrictions, using this thesis as a design guide for new experiments should yield favorable results when applied to new tank designs. If the reader has any questions or would like an updated design process, the author’s preferred contact information can be found using the Orcid iD: 0000-0002-2617-2957 .