Abstract
The goal of our mechanical engineering capstone group was to develop a device that could harvest energy from the altitude changes of an airship/blimp. These aircraft control their altitude using a ballonet system, in which an internal balloon can expand or contract within the outer envelope. This process requires energy which can affect the overall sustainability of the lighter-than-air vehicle. This raised the question of sustainability and aviation, which was essential to explore due to the industry's effect on the environment. Technological inventions such as our group's capstone project play a role in addressing the environmental impact of aviation; however, technology does not exist in a vacuum absent of policy. My STS research therefore investigated to what extent both policy and technology affect the aviation industry’s sustainability.
As has been mentioned, airships and blimps utilize a ballonet system to control their altitude. The ballonet can be filled or deflated with ambient air. This process changes the density of the helium contained in the fixed outer envelope, and a filled ballonet decreases the altitude of the aircraft (helium at higher density) while an empty ballonet increases the aircraft’s altitude (helium at lower density). The process of filling the balloon takes energy, so the goal of our capstone project is to demonstrate a model airship that can harvest electricity from the up-down motion of the airship. To achieve this, a large wooden stand with pulleys wrapped with fishing line was constructed. The fishing line wraps around a DC motor which when spun, acts as a generator. In theory, when attached to the fishing line, the blimp will harvest electricity by pulling the fishing line up and down. Such a proof of concept would demonstrate that the ballonet controlled airship can harvest electricity when encountering a resistance such as the pulleys. This finding can then be applied to developing a propeller system on airships that uses the movement of the surrounding air to harvest energy during altitude change. Such a system would enhance the sustainability of the aircraft.
The research I conducted during my STS studies focused on aviation's sustainability. Principally, I delved into the role that both technology and policy have within the sociotechnical system of the aviation industry. While aviation is not currently a major source of carbon emissions, its proportion of global CO2 is expected to grow as other industries decarbonize. The outsized future impact of aviation makes understanding the possible solutions to its environmental impact essential. Improvements to the industry’s sustainability can arise from new technologies that are more efficient or that minimize the need for fossil fuels. Advancements to sustainability can also be driven by policies that impact procedures in an attempt to reduce emissions. These two methods can both be used to affect change and both are interrelated. Technology can impact policy, while simultaneously policy can impact technology. Acknowledging that these two fields of solutions are inextricably linked, I used a systems analysis lens. The approach also required that groups be formed and a model of interaction created which aligned with my intentions of the research. At the conclusion of my research, the key insight is that the impact of technology in this industry is immense. Ultimately, revolutionary propulsion technologies that eliminate the need for fossil fuels will be what eliminates the impacts of aircraft on the environment. However, an additional insight is that policy can still play a key role as an interim solution in support of technological progress.
When considered in concert, our capstone project and my STS research create a more sustainable path forward for lighter-than-air aircraft. The physical project and STS research also validate the core theory that technology is a key component of sustainable development in the aviation industry. With new technologies, light-than-air aircraft can be made more efficient and have less impact on the environment. Such developments could make the use of such aircraft desirable in fragile ecosystems, one which our planet is quickly becoming.
Notes
School of Engineering and Applied Science
Bachelor of Science in Mechanical Engineering
Technical Advisor: Frank Lagor
STS Advisor: Sean Murray
Technical Team Members: Clarisse Forro, Vivienne Hughes, Troy Meink, Ashlin Schultz, Will Stevens, Richard Yau, Yining Xu
