Generators operating a lower temperatures enable a higher energy density output. The test model was designed to investigate the cooling variables of oil pressure, oil flow rate, number of nozzles, and radial distance of nozzles from the end-turn region. The improved test rig mimics the internal generator geometry and possible cooling configurations. With empirical data, these primary cooling variables were analyzed to develop a heat transfer model to determine the overall heat transfer coefficient. This model considered two separate modes of heat transfer, conduction and convection, occurring in the system. Empirical data used in conjunction with primary assumptions and boundary conditions completed the model and returned the system’s heat transfer coefficient. This improved test model can be applied to almost any generator’s cooling system configuration to optimize performance.

Direct metal laser sintering offers many advantages over traditional casting and forming processes because it can produce complex geometries using materials that cool rapidly due to their specific microstructure and properties. During printing, however, large temperature gradients can develop and cause distortions that render parts unusable for aerospace applications.After an extensive literature search and multilevel, multivariable design of experiments, Inconel 718, a high-temperature alloy powder, was chosen for the print prototype. Alloy selection, build orientation, support structures, layer thickness,and precompensation for distortion were considered in the design of experiments. The turbine blade produced was scanned using blue
light interferometry in order to compare the simulation’s predicted results with a physical print. Metallurgical analysis was performed to evaluate the material properties and microstructure achieved during the printing process. A strong correlation was found between the simulated distortion and the actual distortion of the printed part, indicating that dimensional control in additive manufacturing can be achieved using computer simulation and careful alloy selection.

Auxiliary power units, or APUs, ingest more dust in high-growth regions such as Asia and the Middle East. Dust ingestion causes premature wear to foil bearing surfaces and reduces bearing life. Three different filters were designed that use inertial separation to isolate clean air from dust: a reverse pitot tube, reverse pitot tube with vanes, and a straight tube. Trade-offs in weight, size, cost and performance were made to determine optimal configurations. The filters draw in air by a pressure differential, require no additional parts, and are virtually maintenance free. A flow chamber was designed to simulate the Mach 0.1 flow experienced in APUs. The flow chamber can accommodate the three filter geometries and features the same integration piece used in APUs. The design features a dust release system that disperses dust at a constant rate into the flow chamber. Airflow, efficiency and particle size were tested using this system. Overall, the prototypes either met or exceeded the project requirements.

The sponsor’s sealing criteria are based on experience domain and rule of thumb, rather than being quantifiable criteria supported by testing. Previous capstone projects designed and built a pressure test rig along with multiple sets of flanges. A flange pair from a previous project has been resurfaced to get the surface roughness down to 30 root mean square, which is similar to the sponsor’s specifications. A new flange pair
was designed and created with a few modifications to reduce leakage. The bolt holes were moved closer to the hub to reduce the moment arm, and stronger hardware was used to withstand higher torque values. Finite element analysis was performed on the flange and bolts to understand the structural integrity of the material and ensure there was no plastic deformation on the flanges. A leakage collection and measuring apparatus was designed and built to capture and quantify any leakage from the bolted joint interface. Testing from previous years showed heavy leakage from the bolted joint interface and through the bolt holes. The new capture device fully encloses the bolted joint interface and directs any leaking water to graduated cylinders for measurement. Multiple rounds of testing were conducted with a constant pressure, varying bolt torque values, and leakage was measured multiple times at steady state conditions.

The frangible bearing support is a turbofan engine component designed to break under extreme conditions, such as fan blade-out, to prevent damage to the main structure of the engine. It must, however, be able to withstand icing loads, which are less extreme. Icing loads occur when condensation gathers and freezes inside the engine, creating an imbalance on the main shaft and imparting a rotating load on the frangible bearing support. The frangible bearing support was recently redesigned to meet a stricter icing life requirement of 5,000 pounds radial load for 30 million cycles.The new test rig design simulates high-cycle fatigue under icing conditions. The cycle count for this test was adjusted to 100,000 cycles with a rotating load of 8,500 pounds, applied radially outward on the inner cylindrical wall of the frangible bearing support. The test rig applies the load through the use of two actuators with connections to a puck in the center of the frangible bearing support. The test rig was designed to last 250,000 cycles so it can test both the original and redesigned frangible bearing support.

Feather seals are used to seal the gaps between the stator vanes in the turbine section of the engine. Currently, there is no way to evaluate leakage through these seals on an operating jet engine, nor does the sponsor have a static test rig that can quantify this air mass leakage. A static test rig was designed that uses sonic nozzles in the choked flow condition. The rig measures ambient pressure and pressure differentials upstream and downstream of these nozzles, and the temperature inside the pressure vessel. The test rig takes in compressed shop air, which flows through sonic nozzles maintained in the choked flow condition by pressure differentials. The pressurized air enters a pressure vessel that houses six feather seals. The small amount of air that flows past the feather seals and into the atmosphere can be quantified using pressure and temperature data. This data can then be used to calculate air mass flow through the feather seals. The rig can test six seals of the same design at once, allowing average leakage to be calculated for any given design. A variety of seal designs can be installed and tested in the rig to determine which design creates the best seal.

The sponsor transports components ranging from rocket motors to avionics equipment throughout the United States. Harsh transportation events experienced in transit can affect the functionality of components by shortening their lives. The team designed a device to record pertinent data for analysis and determination of component flight-worthiness after transportation.The event data recorder detects whether the cargo shipped has been subjected to events that exceed the design or specified control limits. Information from the event data recorder allows the sponsor to decide if the item meets minimum end-of-life requirements. During transit, data is recorded relating to structural displacement and environmental conditions. The recorder also has room for additional external transducers, such as digital and analog sensors to measure acceleration and vibration. The device houses three internal sensors to monitor six degrees of freedom, temperature and humidity. The data recorder continuously monitors all operational sensor channels for trigger events that exceed specified threshold conditions, which are set before installation by plugging in a USB 2.0 cord and changing the appropriate threshold parameters. When a trigger event is detected, the recorder saves sensor data for a user-specified duration before and after the trigger. Sensor data is downloaded after the shipment reaches its destination.

The primary application of an alignment telescope is as a reliable optical reference for examining and characterizing external test optics, which it achieves via collimation,
autoreflection and retroreflection of projected light and comparison of a reference image, often as reticles or crosshairs. The large aperture alignment telescope is distinguished by a clear aperture of over 80 millimeters, double that of most alignment telescope, which allows for a greater field of view. The optical design of a large aperture alignment telescope is optimized for a unique self-contained 528-nanometer monochromatic light source. The large aperture alignment telescope allows for return images to be observed by a standard test camera or traditional eyepiece, depending on user needs and preference. Images can be focused at working distances of 14 inches to infinity while taking up less than two feet of space on an optical workbench.

Tucson Electric Power offers several different rate plans to customers, including a low-cost plan that entices customers to use more power during non-peak times.The system designed consists of devices that monitor energy consumption by five domestic appliances, and Wi-Fi communication with a server-based open-source web framework built using Django. The result is a database that can be analyzed via user interface, which displays energy consumption and cost, and suggests the best rate plan based on data collected from devices and price points set by Tucson Electric Power. The system allows consumers to save money and optimize power use while lowering demand for the provider during peak times.

Pantry for Good is an open-source application that provides food banks with a way to manage inventory, donor tracking and client intake. The team conducted a gap analysis of Pantry for Good and concluded it was missing some key features. Rather than creating a competing website with similar functionality, the team added new features to those already offered by the application. The new functionalities included a simple, intuitive volunteer-scheduling platform, an automated donation-weighing interface, and a convenient mass imports feature. The team used open-source software development kits, multiple software modules, and embedded systems to enhance Pantry for Good’s ability to help food banks around the world manage their operations.