Engineering Commons^™

A Computational Analysis Of The Aerodynamics And Aeroacoustics Of Jets With Fluid Injection, Marco Coderoni

Doctoral Dissertations and Master's Theses

A detailed numerical analysis of fluidic injection as a tool to reduce noise emission is presented here. The noise reduction strategy, developed at the Pennsylvania State University, is based on injectors that blow air into the diverging section of the nozzle to emulate the effect of interior corrugation on the jet plume. The advantage is that the injection can be activated during takeoff and turned o_ during other phases of flight so that performance is not affected. Numerical simulations are performed on a military-style nozzle based on the GE F400-series engines, with a design Mach number of 1:65, for over-expanded …

Surgical And Medical Applications Of Drones: A Comprehensive Review, James C. Rosser, Vudatha Vignesh, Brent A. Terwilliger, Brett C. Parker

Publications

Background: Drones have the ability to gather real time data cost effectively, to deliver payloads and have initiated the rapid evolution of many industrial, commercial, and recreational applications. Unfortunately, there has been a slower expansion in the field of medicine. This article provides a comprehensive review of current and future drone applications in medicine, in hopes of empowering and inspiring more aggressive investigation. Database: A literature search was performed by EBSCO (Elton B. Stephens Company) Discovery Service, searching the phrases "drones," "UAV," "unmanned aerial vehicles," "UAS," and "unmanned aerial systems." A second search was used to identify sources that contained …

Surgical And Medical Applications Of Drones: A Comprehensive Review, Brent Terwilliger, James C. Rosser Jr., Vudatha Vignesh, Brett C. Parker

Publications

Drones have the ability to gather real time data cost effectively, to deliver payloads and have initiated the rapid evolution of many industrial, commercial, and recreational applications. Unfortunately, there has been a slower expansion in the field of medicine. This article provides a comprehensive review of current and future drone applications in medicine, in hopes of empowering and inspiring more aggressive investigation.

Aerothermodynamic Analysis Of A Mars Sample Return Earth-Entry Vehicle, Daniel A. Boyd

Mechanical & Aerospace Engineering Theses & Dissertations

Because of the severe quarantine constraints that must be imposed on any returned extraterrestrial samples, the Mars sample return Earth-entry vehicle must remain intact through sample recovery. Vehicles returning on a Mars-Earth trajectory will attain velocities exceeding any that have been experienced by prior space exploration missions, with velocities approaching 14 km/s. Velocities as high as these will encounter significant heating during atmospheric re-entry to Earth.

The purpose of this study has been to systematically investigate the aerothermodynamic challenges that will result from a Mars sample return, Earth-entry vehicle design. The goal was to enable efficient estimation of maximum stagnation …

Direct Numerical Simulations Of Incompressible Flow Through Porous Packs Over A Wide Range Of Reynolds Numbers, Antoine Michael Diego Jost

Theses and Dissertations

Direct numerical simulations of incompressible flow through periodic square/rectangular (two-dimensional; 2-D) and cubic (three-dimensional; 3-D) arrays of particles and periodic random packs of polydisperse spheres over a wide range of Reynolds numbers and at various porosities are performed. The unsteady Navier- Stokes equations are solved with either a 3-D parallel finite-difference (FD) inhouse research code on a collocated Cartesian grid and with an immersed boundary method (IBM) to treat the internal boundaries, or with the finite-volume (FV) solver OpenFOAM R⃝ on an unstructured grid and with an explicit treatment of the boundaries. The FD explicit solver is used for 2-D …

Catalytic Augmentation Of An Arc-Ignited Hydrogen Peroxide/Abs Hybrid Rocket System, Stephen A. Whitmore, Christopher J. Martinez

Mechanical and Aerospace Engineering Faculty Publications

The authors have collaborated with an industry partner to develop a prototype upper stage for a dedicated nano-launch vehicle. In addition to providing sufficient impulse for orbit insertion, the unique motor system also provides capability for multiple restarts; allowing operation as an orbital maneuvering thruster. The hybrid motor design uses 85%-90% hydrogen peroxide solution and 3-D printed ABS as propellants. In the original system design the peroxide catalyst bed was completely removed and a patented arc-ignition system thermally ignited the propellants. The thermal ignition system was effective but resulted in a combustion latency of approximately 1-second, reducing overall performance and …

Flip-Chip (Fc) And Fine-Pitch-Ball-Grid-Array (Fpbga) Underfills For Application In Aerospace Electronics—Brief Review, Ephraim Suhir, Reza Ghaffarian

Mechanical and Materials Engineering Faculty Publications and Presentations

In this review, some major aspects of the current underfill technologies for flip-chip (FC) and fine-pitch-ball-grid-array (FPBGA), including chip-size packaging (CSP), are addressed, with an emphasis on applications, such as aerospace electronics, for which high reliability level is imperative. The following aspects of the FC and FPGGA technologies are considered: attributes of the FC and FPBGA structures and technologies; underfill-induced stresses; the roles of the glass transition temperature (T_g) of the underfill materials; some major attributes of the lead-free solder systems with underfill; reliability-related issues; thermal fatigue of the underfilled solder joints; warpage-related issues; attributes of accelerated life …

Effects Of Automated Fiber Placement On High Strain Rate Compressive Response Of Advanced Composites, Alexander Trochez

Mechanical & Aerospace Engineering Theses & Dissertations

Automated Fiber Placement (AFP) technology shows great promise in manufacturing carbon fiber composite structures. However, intermittent defects occur in the process that can affect the overall mechanical performance of the structure. The aim of this work is to investigate the effects of deliberately placed principal defects (Gap, Overlap, and Fold) on the compressive response under quasistatic (strain rate ~10^-3 s^-1) and dynamic (strain rate ~10³ s-1) loading conditions. The controlled defects were placed at the laminate level in different orientations and depths. High strain rate compression experiments were conducted using a split Hopkinson pressure bar (SHPB) …

Control Laws For Autonomous Landing On Pitching Decks, Kendrick Buchala

Theses and Dissertations

This thesis addresses the problem of landing a quadcopter onto the pitching deck of a ship, as a partial simulation of a shipboard landing during high seas. The deck is modeled to pitch with a sinusoidal motion. While shipboard landing consists of many stages, only the final landing is simulated in this research. Other ship motions, such as roll and heave, are likewise not considered. The goal is to land the quadcopter in the center of the deck with minimal position and pitch error, where position error measures how far fore or aft of the center of the landing pad …

Dynamics Of Spacecraft Orbital Refueling, Casey Clark

Theses and Dissertations

A quantitative collation of relevant parameters for successfully completed experimental on-orbit fluid transfers and anticipated orbital refueling future missions is performed. The dynamics of connected satellites sustaining fuel transfer are derived by treating the connected spacecraft as a rigid body and including an internal mass flow rate. An orbital refueling results in a time-varying local center of mass related to the connected spacecraft. This is accounted for by incorporating a constant mass flow rate in the inertia tensor. Simulations of the equations of motion are performed using the values of the parameters of authentic missions in an endeavor to provide …

Simulation Of Radiation Flux From Thermal Fluid In Origami Tubes, Robert R. Bebeau

USF Tampa Graduate Theses and Dissertations

Spacecraft in orbit experience temperature swings close to 240 K as the craft passes from the shadow of the Earth into direct sunlight. To regulate the craft’s internal energy, large radiators eject unwanted energy into space using radiation transfer. The amount of radiation emitted is directly related to the topology of the radiator design. Deformable structures such as those made with origami tessellation patterns offer a mechanism to control the quantity of energy being emitted by varying the radiator shape. Three such patterns, the Waterbomb, Huffman Waterbomb, and Huffman Stars-Triangles, can be folded into tubes. Origami tubes offer greater control …

Static Performance Results Of Propellers Used On Nano, Micro, And Mini Quadrotors, Robert W. Deters, D. Dantsker, S.C. Kleinke, Narcrisha Norman, Michael S. Selig

Publications

An increase in the number of small quadrotors has created the interest in having performance data on the propellers used by these aircraft. With an aircraft size less than 5 in and propellers diameters less than 3 in, these quadrotors are typically referred to mini, micro, or nano by hobbyists and manufacturers. The size of the propellers used on these aircraft operate at low Reynolds numbers that are typically less than 50,000 for diameters up to 3 in and less than 20,000 for diameters up to 2 in. Static performance testing of the propellers used on 11 small quadrotors was …

Book Review: Fundamentals Of International Aviation, Alan Bender

International Journal of Aviation, Aeronautics, and Aerospace

Not applicable.

Creep Of Hi-Nicalon™ S Ceramic Fiber Tows At 1100°C In Air And In Silicic Acid-Saturated Steam, Logan M. Gumucio

Theses and Dissertations

Innovations in SiC based ceramic matrix composites (CMCs) have yielded exceptional high-temperature properties and performance in aggressive oxidizing environments. These material characteristics provide potential avenues for future advancements in many applications where current metallic alloys perform near their operating temperature limits in a harsh environment. As steam (typically present in these environments) enters through cracks in the matrix of a SiC/SiC composite, it leaches Si and becomes saturated with silicic acid, Si(OH)₄, prior to attacking the reinforcing SiC fibers. Therefore, it is paramount that a thorough understanding of the performance and durability of SiC fibers be obtained under …

Mitigating Interference With Knowledge-Aided Subarray Pattern Synthesis And Space Time Adaptive Processing, Yongjun Yoon

Theses and Dissertations

Phased arrays are essential to airborne ground moving target indication (GMTI), as they measure the spatial angle-of-arrival of the target, clutter, and interference signals. The spatial and Doppler (temporal) frequency is utilized by space-time adaptive processing (STAP) to separate and filter out the interference from the moving target returns. Achieving acceptable airborne GMTI performance often requires fairly large arrays, but the size, weight and power (SWAP) requirements, cost and complexity considerations often result in the use of subarrays. This yields an acceptable balance between cost and performance while lowering the system’s robustness to interference. This thesis proposes the use of …

Competitiveness Of Hybrid Electric Aircraft On Short Range Scheduled Flights, Johannes Anton, Hans-Joachim K. Ruff-Stahl

International Journal of Aviation, Aeronautics, and Aerospace

Hybrid electric aircraft are expected to enter the small regional aircraft market within the next two decades. The aim of this study was to investigate if a hybrid electric passenger aircraft with 50 seats can be competitive against the established 100 seat aircraft on short range scheduled flights. The Embraer EMB 145 and EMB 190 regional jets were chosen as benchmarks for that market. A hypothetical hybrid version of the EMB 145 with increased fuel efficiency was tested on a cost per available seat mile (CASM) basis. The t tests confirmed significant (p < 0.05) competitiveness of the hybrid version, while in contrast the conventional 50-seater was significantly more expensive compared to the 100seat aircraft. This indicates that hybrid aircraft could enter the short haul market with a competitive advantage, even against the established 100 seat regional jets.

The Pocketqube Standard: Issue 1, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A report titled "The PocketQube Standard Issue 1" published on June 7, 2018.

An Evaluation Of Ultrasonic Shot Peening And Abrasive Flow Machining As Surface Finishing Processes For Selective Laser Melted 316l, Rhys Gilmore

Master's Theses

Additive Manufacturing, and specifically powder bed fusion processes, have advanced rapidly in recent years. Selective Laser Melting in particular has been adopted in a variety of industries from biomedical to aerospace because of its capability to produce complex components with numerous alloys, including stainless steels, nickel superalloys, and titanium alloys. Post-processing is required to treat or solve metallurgical issues such as porosity, residual stresses, and surface roughness. Because of the geometric complexity of SLM produced parts, the reduction of surface roughness with conventional processing has proven especially challenging. In this Thesis, two processes, abrasive flow machining and ultrasonic shot peening, …

Orbital Constellation Design And Analysis Using Spherical Trigonometry And Genetic Algorithms: A Mission Level Design Tool For Single Point Coverage On Any Planet, Joseph R. Gagliano

Master's Theses

Recent interest surrounding large scale satellite constellations has increased analysis efforts to create the most efficient designs. Multiple studies have successfully optimized constellation patterns using equations of motion propagation methods and genetic algorithms to arrive at optimal solutions. However, these approaches are computationally expensive for large scale constellations, making them impractical for quick iterative design analysis. Therefore, a minimalist algorithm and efficient computational method could be used to improve solution times. This thesis will provide a tool for single target constellation optimization using spherical trigonometry propagation, and an evolutionary genetic algorithm based on a multi-objective optimization function. Each constellation will …

Investigating Forward Flight Multirotor Wind Tunnel Testing In A 3-By 4-Foot Wind Tunnel, Reed Danis

Master's Theses

Investigation of complex multirotor aerodynamic phenomena via wind tunnel experimentation is becoming extremely important with the rapid progress in advanced distributed propulsion VTOL concepts. Much of this experimentation is being performed in large, highly advanced tunnels. However, the proliferation of this class of vehicles extends to small aircraft used by small businesses, universities, and hobbyists without ready access to this level of test facility. Therefore, there is a need to investigate whether multirotor vehicles can be adequately tested in smaller wind tunnel facilities. A test rig for a 2.82-pound quadcopter was developed to perform powered testing in the Cal Poly …

Use Of Manifolds In The Insertion Of Ballistic Cycler Trajectories, Oliver K. Morrison

Master's Theses

Today, Mars is one of the most interesting and important destinations for humankind and copious methods have been proposed to accomplish these future missions. One of the more fascinating methods is the Earth-Mars cycler trajectory which is a trajectory that accomplishes repeat access to Earth and Mars with little to no fuel-burning maneuvers. This would allow fast travel to and from Mars, as well as grant the possibility of multiple missions using the same main vehicle.

Insertion from Earth-orbit onto the cycler trajectory has not been thoroughly ex- plored and the only existing method so far is a Hohmann-esque transfer …

Electrode Geometry Effects In An Electrothermal Plasma Microthruster, Harrison Raymond King

Master's Theses

Nanosatellites, such as Cubesats, are a rapidly growing sector of the space industry. Their popularity stems from their low development cost, short development cycle, and the widespread availability of COTS subsystems. Budget-conscious spacecraft designers are working to expand the range of missions that can be accomplished with nanosatellites, and a key area of development fueling this expansion is the creation of micropropulsion systems. One such system, originally developed at the Australian National University (ANU), is an electrothermal plasma thruster known as Pocket Rocket (PR). This device heats neutral propellant gas by exposing it to a Capacitively Coupled Plasma (CCP), then …

Parametrization Of Triple Screw Pumps For Aerospace Applications, Allison Putira

Doctoral Dissertations and Master's Theses

Triple Screw Pumps, a form of positive displacement pump, offer steady, high-pressure flow. In very small launch vehicles or upper stages turbopumps are not practical. This paper examines the performance of triple screw pumps to determine if they may serve as an alternative to turbopumps for use in small launch vehicles or upper stages. To this end, the geometry of the screws is first determined from the relative sizes of the screws and tooth height. From this — along with the screw angle and screw clearance — the performance parameters of flow rate, output pressure, and efficiency can be computed. …

Interplanetary Transfer Trajectories Using The Invariant Manifolds Of Halo Orbits, Megan S. Rund

Master's Theses

Throughout the history of interplanetary space travel, the Newtonian dynamics of the two-body problem have been used to design orbital trajectories to traverse the solar system. That is, that a spacecraft orbits only one large celestial body at a time. These dynamics have produced impressive interplanetary trajectories utilizing numerous gravity assists, such as those of Voyager, Cassini, Rosetta and countless others. But these missions required large amounts of delta-v for their maneuvers and therefore large amounts of fuel mass. As we desire to travel farther and more extensively in space, these two-body dynamics lead to impossibly high delta-v values, and …

Modification Of A Ground Based Atomic Oxygen Simulation Apparatus To Accommodate Three Dimensional Specimens, Charles Ward

Master's Theses

The space environment presents various challenges when designing systems and selecting materials for applications beyond Earth’s atmosphere. For mission success, these challenges must be considered. One of the detrimental aspects of the space en- vironment is Atomic Oxygen, AO. Only present in harmful quantities in Lower Earth Orbit, LEO, AO causes significant damage to materials by breaking molecular bonds. California Polytechnic State University’s, Cal Poly’s, space environments laboratory features an apparatus capable of simulating this environment. Very thin or short samples were tested to observe the mass loss due to erosion of the sample material. Recent modifications to the system …

The Effects Of Varying Composition And Build Direction On Direct Metal Deposition Fabricated Inconel 718, Abigail P. Nilan, Jessica M. Fordham

Materials Engineering

Inconel 718 (IN718) is a popular wrought superalloy, and is currently being investigated for additive manufacturing (AM) applications in the aerospace industry. However, overaging and the presence of microcracks have caused a significant reduction in properties. The purpose of this study is to meet or exceed the mechanical properties of wrought IN718 by varying the composition and build direction of the AM alloy. Alternative compositions were selected with Oerlilon Metco’s Rapid Alloy Development (RAD) software, and differ in niobium content, which increases the fraction of the primary strengthening phase (γʺ). Direct metal deposition (DMD) was used to fabricate the samples, …

Thermal Vacuum Chamber Refurbishment And Analysis, Adrian Michael Williams

Master's Theses

Spacecraft are subject to different environments while on orbit around the Earth and beyond. One of the most critical of these environments that must be counteracted is the thermal environment. Each spacecraft has an operating temperature that is specified in the mission requirements. The requirement stems from internal component operating temperatures that are critical to mission success. Prior to placing the spacecraft in orbit, engineers must be sure that the spacecraft will survive or risk losing the mission entirely.

The primary way to mitigate this risk is to use a thermal vacuum chamber (TVAC). The chamber is designed to resemble …

The Design And Implementation Of A Supersonic Indraft Tube Wind Tunnel For The Demonstration Of Supersonic Flows, Daniel Kenneth Johnson

Master's Theses

Historically, the endeavor of scale testing flight vehicles at supersonic Mach numbers, especially for long durations, has required the development of closed-loop wind tunnels, which are extremely expensive both to build and operate due to the high complexity and incredible power required to drive such a system. The intermittent blowdown wind tunnel, indraft tunnel, and shock tunnel have alleviated many of these cost requirements to some degree, whilst facilitating testing at very high Mach numbers and enthalpies; however, these systems require the handling of gases at pressures and temperatures that can be prohibitive for many university settings. The Ludwieg tube …

Determining Feasibility Of A Propulsionless Microsatellite Formation Flight Mission, Aaron Levis

Master's Theses

Benefits of developing missions with multiple formation flying spacecraft as an alternative to a traditional monolithic vehicle are becoming apparent. In some cases, these missions can lower cost and increase flexibility among other situational advantages. However, there are various limitations that are imposed by these missions that are centered on the concept of maintaining the necessary formation. One such limitation is that of the propulsion system required for each spacecraft. To mitigate the complexity and mass of the onboard propulsion, the pairing of electromagnetic actuators and differential drag to replace the functionality of a propulsive system is investigated. By using …

Evaluation Of Electrochemical And Laser Polishing Of Selectively Lasermelted 316l Stainless Steel, Julian R. Lohser

Master's Theses

Selective laser melting has shown incredible growth as a metallic additive manufacturing process in recent years. While it does provide many solutions and new ways to approach challenges, it does not come without issues of its own, namely, surface roughness. In the as-printed state, the surface roughness of selectively laser melted parts is unacceptable for use in engineering applications. Additionally, selective laser melting is used to produce complex geometries with hard to reach features, preventing conventional mechanical polishing from being successful. Therefore, it is necessary to evaluate non-mechanical polishing processes as treatments for surface roughness. In this study, electrochemical and …