The objective of this project was to repurpose a commercial smoke detector for use as a particle sensor on board an aircraft. The sensor software was modified using the Python programming language to extract obscuration data at 3-second intervals. The 3-second interval was necessary for response calibration. Particle response tests were conducted with an aerosol generator and two analyzers to determine the particle size and concentration response of the smoke detector. A robust mount was designed and assembled to fit the sensor and allow attachment near the air-circulation duct on the aircraft. Finite element analysis was performed and the mount was fitted with foam capable of absorbing at least 4 g of shock. Temperature tests were also conducted to see if the sensor could handle the temperature fluctuations typical on board aircraft.

Composites made using carbon-fiber-reinforced polymers, or CFRPs, are widely used in aerospace applications because of their stiffness and low weight, but their mechanical properties after processing, such as drilling, are not well understood. Software can emulate the mechanical behavior of CFRPs but physical tests are needed to validate such models are needed. The goal of this project is to quantify mechanical properties of CFRPs for a specific application using tests defined by the American Society for Testing and Materials. Acoustic perforated panels help reduce noise pollution inside aircraft, and CFRPs would be an ideal material for these panels, but would require extensive drilling. Because CFRPs are highly abrasive and tend to delaminate, high-speed steel drill bits quickly suffer catastrophic wear. The team ran ASTM tests to evaluate the tensile, shear, and compressive strength of the CFRPs before and after perforations. As part of the project, the team made a critical make/buy decision to produce the panels, made processing decisions to prepare testing specimens to specifications, oversaw material processing, ran the ASTM tests, and documented all results.

Airborne particles sucked into turbine engines can erode internal parts, necessitating extensive maintenance and increasing the possibility of failure. This project’s objective is to separate particles from an airstream and reduce internal erosion. The design uses an in-line swirl particle separator that relies on centrifugal forces to remove particles from an airstream. A swirler, consisting of rotated blades extending at 90 degrees from a central cylinder, is placed at the front of the separator system. The swirler forces the airflow to spin as it hits the blades, generating centrifugal forces that throw particles to the outer edge of the separator as they travel down the migration chamber to be removed from the system at the diffuser gap. The cleaned air flows through the outlet of the separator and into the turbine engine inlets. To optimize the particle separation of the system, a design of experiments was performed with three factors: inlet diameter, swirler length, and migration chamber length. Each factor had two levels: high and low. All combinations of the three factors at each of the two levels were tested and an analysis completed to determine the optimal design choice for each factor.

The goal of this project is to design a power transformer using printed circuit boards as windings. If the boards have a sufficiently high number of layers, it is possible to complete enough windings for an effective transformer. The designed board contains 12 copper layers that act as windings. Layers are connected using a vertical interconnect access, or VIA, and the boards are stacked together to make a complete transformer. The two main focus areas of the project are the layout of the boards and their thermal performance. The layout design concentrated on the pattern of VIAs and shape of the copper layers. The boards have been designed to connect from layer to layer to ensure full windings around the core. The VIAs have also been arranged in such a way that the VIAs don't short on each other when the boards are stacked. Transformers generate heat, so it is important to minimize the heat buildup, which could melt the boards. A thermal analysis was performed using SolidWorks to keep boards below their melting temperature. Due to budget and time constraints, building a complete transformer was not feasible. Instead, a small prototype consisting of three boards stacked together was built, which proved that the repeatable layout design is feasible and that the complete transformer will not melt under normal load.

A small engine in the tail of most commercial airliners, called an auxiliary power unit, satisfies the aircraft’s power needs during boarding and refueling, such as air conditioning, lighting, pilot controls and in some cases engine startup. After passenger safety, reducing aircraft weight is a major aviation concern. If one of the rotors in the auxiliary power unit fails, it could exit the engine and cut through the aircraft cabin. The goal of this project is a design that will contain rotors in the event of a failure, and that weighs a little as possible without compromising passenger safety. This is achieved by placing containment rings outside the turbine and compressor rotors. The nickel-based alloy rings can stretch and absorb the impact of pieces from a fractured rotor. The design was tested using proven mathematical models and analysis. Cost precluded a real-world test, but the team developed a test plan should Honeywell decide to continue with the design.

The Deep Water Sensor System is a complete subsea package for remotely sensing water conditions over long distances. It consists of an interacting base station and tethered remote sensing unit capable of communicating data. The remote station uses temperature, pressure, and pH sensors to take measurements and characterize the quality of the water. The remote sensing unit is enclosed in a water-resistant case for deep-sea capability. The tether, which connects the base station and sensing unit, is a low-resistance twisted pair enabling a 4-20 milliamp current loop, which is ideal for the transmission of high-integrity electrical signals and an effective data-communication method in long-range applications. The base station interprets signals from the remote sensing unit using a highway addressable remote transducer compatible communication protocol. The base station compiles and illustrates the data using the LabVIEW graphical user interface. A Texas Instruments MSP-430 microcontroller unit is used in both the remote sensing unit and the base stations.

Toilets account for about 30 percent of home water usage, and the EPA estimates that household water leaks add up to more than a trillion gallons a year, over 10,000 gallons per household. The economic and environmental costs of these preventable household leaks are substantial. Current low-cost leak-detection systems are unreliable and require human intervention, so the project sponsor challenged the team to design a better way to prevent water loss due to leaks. The team designed a low-cost, autonomous water shutoff device that integrates with common household toilets and runs continuously off a 9-volt battery. A latching two-way solenoid valve is installed at the wall angle stop and connected to a control box and power source on the side of the toilet tank. An adjustable timer is set to account for variations in fill rate and water pressure that cause flush time to vary. The control system is connected to a waterproof momentary pull switch installed in series with the flapper chain. The switch is triggered upon flushing which causes the valve to open for the duration of the tank fill time, after which the valve closes again, protecting against slow intermittent leaks, constant leaks and flooding.

The purpose of this project was to construct a prototype platform that integrates focused microwave therapy and thermoacoustic imaging systems to deliver thermal therapy to a tissue while mapping its temperature in real time. Focused delivery of microwave thermal energy to a region of tissue can potentially be used as a noninvasive treatment for tumor reduction, but the heating needs to be constantly monitored to ensure that proper temperatures for tumor ablation are reached while the surrounding healthy tissue is not damaged. Current clinical methods for this monitoring are expensive and time consuming. This project will serve as a proof of concept for an integrated FMT-TI system to selectively heat and safely monitor different regions in tissue. The design includes a microwave generation, power amplification, and distribution network that delivers microwaves through specially designed patch antennas into a phantom tissue to heat a specified focal region. The tissue’s change in temperature is monitored by the FMT-TI system while it delivers secondary short-pulse microwaves through a waveguide into the tissue to induce an acoustic pressure wave, which is recorded by a scanning ultrasound transducer. This signal is processed and converted into a heat map displaying temperature intensity across a region of space.

The objective of this project is to design, develop, and test an autonomous surveillance system able to track objects without human intervention. The autonomous aerial tracking system developed by the team will be used in the International Aerial Robotics Competition in August 2016. Competition requirements stipulate that the unmanned aerial vehicle cannot use GPS, and that it must remain below 3 meters above the ground at all times. The competition arena is a 20-by-20-meter grid, which forces the detection device to have a large field of view. It must also be able to locate several small, mobile robots traversing the grid. The system uses four Pixy CMUcam5 cameras and an ELP 180 degree fisheye USB camera for detection. The system must provide the locations, velocities, and headings of the robots, in addition to its own location, velocity, and heading. All calculations are done onboard by a Raspberry Pi microcontroller and sent directly to the drone’s autopilot, which makes decisions on vehicle and robot movement based on information processed.

This project required the team to develop a system to monitor the concentration of an ionic buffer solution dispensed onto a standard 75x25 mm microscope slide. Because some tests done by Ventana are extremely sensitive to the ionic concentration of the on-slide fluid, the company wants a way to measure ionic concentration noninvasively. Evaporation and replenishment of the fluid containing the tissue sample cause variation in ionic concentration, which can adversely affect the quality of histopathology staining. The designed system uses a refractometer to measure in real time the refractive index of the buffer solution, which correlates with ionic concentration. When evaporation raises the ionic concentration, a technician can add a precise volume of buffer solution to compensate. By using an infrared laser to refract light into the solution and onto a complementary metal-oxide semiconductor sensor, the resulting angle of refraction can be used to assess the concentration as a function of temperature. A graphical user interface, which allows the user to measure concentration see it change over time, is implemented using a touch screen and Raspberry Pi microcontroller.