Theses and Dissertations at Montana State University (MSU)
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733
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Item Wireless sensor network development for the purpose of measuring acceleration in snow(Montana State University - Bozeman, College of Engineering, 2023) Lesser, James Byron; Chairperson, Graduate Committee: Edward E. AdamsA WSN (Wireless Sensor Network) was developed for the purpose of measuring snow acceleration in response to loading of various types. In its current state, the WSN is composed of seven nodes (radio enabled sensors) and one controller. Two dynamic ranges, +/- 10 g and +/- 40 g, allow for user adjustment based on the required sensitivity of measurement. Acceleration data is logged simultaneously across all active nodes; data from an analog accelerometer is stored by each node on a microSD card. Data throughput limits the maximal sampling frequency to 10 kHz at 8-bit precision, or 5 kHz at 10-bit precision. Empirical investigation of GEM (Green Environmental Monopropellant) as a tool for avalanche mitigation was conducted with the first iteration of the WSN. The GEM explosive is compared with the industry standard, Pentolite; the metrics of comparison are those of overpressure, impulse per unit area, and the resulting snow acceleration. This study showed the effectiveness of the WSN as a tool for measuring snow dynamic response under explosive loading. Additionally, an ECT (Extended Column Test) instrumented with the WSN on this day elicited continued development of the WSN. A detailed look at the components of the WSN provides the physical and electrical qualities focused on the nodes intended environment - seasonal snow. Theory of operation, and a standard operating procedure, provide fundamental knowledge for the end user. Modal testing was performed to characterize the vibration response of the node. Natural frequencies are identified within the bandwidth of the accelerometer, and it is shown that these frequencies are not present in signals collected in snow under impulsive loading. Acceleration data acquired by the WSN in a series of stability tests, conducted in the lab and in the field, demonstrate the utility of the system.Item Measuring explosive airblast of remote avalanche control systems(Montana State University - Bozeman, College of Engineering, 2021) Seitz, Brandt Kolden; Chairperson, Graduate Committee: Robb LarsonThis research was established to evaluate the explosive blast waves from operational remote avalanche control systems (RACS). Testing was performed on Gazex, O'Bellx, and Wyssen Tower systems installed near Alta, Utah. Air pressures were measured in many directions and at a range of distances around each explosive using high-pressure microphones and custom measurement equipment. The air pressure data from each system was then evaluated based on the peak pressures generated, effective blast wave energy, the rate at which pressure increased, and the decay of these parameters with distance. Distinct differences, and some similarities, between the explosives tested were found that both validated and expanded upon previous research efforts. It was found that an 11-lb Pentolite charge (designed to be deployed from a Wyssen Tower) had the strongest effects overall, followed by the standard 11-lb gel emulsion charge from a Wyssen Tower, then by the 1.5 m 3 Gazex system (which was comparable to the gel charge in the direction of the exploder, but weaker in other directions), and lastly by the O'Bellx system (which had a more localized, but more symmetric, effect than the Gazex). In addition, many other tests were conducted utilizing 2-lb Pentolite charges, simulated Avalanche Guard charges, flat-field testing of Wyssen Tower gel emulsion and Pentolite charges, and explosives or RACS placed near unique terrain features. The 2-lb Pentolite testing validated the instrumentation for this project and showed that the equipment performed similarly to other systems from prior research efforts. The simulated Avalanche Guard charge was shown to have a very similar effect to the 11-lb gel emulsion charge. Flat-field testing of the Wyssen Tower charges showed similar blast wave strengths as was observed at the operational tower but indicated differences in the symmetry of the waves when compared to the operational tower. Lastly, the initial investigation of terrain features indicated that features such as cliffs and gullies can increase the directionality of an explosive. Overall, this work will provide avalanche control experts with much needed performance data on operational RACS and will also help to facilitate future work in this subject area.