Project Orca, University of Washington Human Powered Submarine
As an undergraduate engineering team at the University of Washington, our main goal as the Human Powered Submarine team is to provide our roughly 50 team members with as much real engineering experience as possible by designing, manufacturing, testing, and racing a competitive human powered submarine. We believe that the experience we gain will propel us into our post graduate engineering careers. Given our philosophy, this year we decided to take a more sustainable approach to our normal engineering practices.
Each year our team engineers a new submarine for a given competition by building on past designs, and pursuing new innovation challenges. We use the same hull for two years in a row, and every other year we design and manufacture a new and improved version. This school year (2020-2021), we will be manufacturing a new hull.
In years past, we have almost always manufactured our hull using a carbon fiber polymer reinforced composite layup process. All the materials used in this process are very detrimental to the environment. The production of carbon fiber releases a significant amount of greenhouse gasses into the atmosphere as well as being about 14 times as energy intensive as steel manufacturing. In addition, the epoxy resins normally used in the manufacturing process are plastics that create a lot of waste and tend to sit in landfills after use.
In order to reduce our carbon footprint as an engineering team, give our members valuable sustainable engineering experience, and set a sustainable example for other engineering clubs, we have decided to manufacture our submarine hull using a sustainable and natural process. After researching for the duration of autumn quarter, we have decided to manufacture our submarine hull using natural flax fiber and a recycled foam core in a resin infusion layup process. This material has been proven in many other applications so we expect it to be very feasible for our intentions. We are seeking $2000 in funding for the purchase of these sustainable materials for our hull.
Our work will be conducted in several lab and manufacturing shop locations at the mechanical engineering building. Our members have already assisted in the research and sustainable design of the hull and will continue to assist in manufacturing the submarine hull throughout the remainder of the school year, under the supervision of our team leads and guidance of our faculty mentors.
The Human Powered Submarine team consists of 50 students in various engineering and engineering undeclared majors. The team is split up into six sub-teams who are responsible for different systems within the submarine. These sub-teams include: drivetrain, controls, propulsion, hull, electronics, and dive and safety. Each of these sub-teams are made up of anywhere from 2 to 15 members led by a team lead. The team as a whole is overseen by a technical director and an administrative director. Each respective sub-team works on a different aspect of the submarine, and it is the hull team’s job to design, manufacture, and test the new hull.
Project Orca consists of the manufacture of our composite hull using the resin infusion layup composite manufacturing technique. As hull team lead, I, Alex Bartoletti, am responsible for leading members of the hull team to complete this process. These team members will be directly involved in the hands-on processes of preparing the hull mold, practice layups, preparing the flax fiber for layup, vacuum sealing, epoxy matrix infusion, and post processing of the hull. These members will attend or have already attended safety training in the Mechanical Engineering Composites Prototype Lab and will continue to learn about best practices while working with composites from our team’s industry sponsors.
About 7-10 members will be involved in preparation of the female hull tooling mold at various stages. We will receive the mold as sheets of raw foam from the manufacturer and 1-2 members will spend about 2 hours gluing sheets together and cutting off extra sections in order to create a block of foam out of which the tooling mold can be machined. Once the machine work is finished, multiple members will work on the mold at separate times to clean the mold surfaces, seal the foam, smooth the surface and add mold release to the mold surface. This is a significant amount of prep work that will require research and hands on participation from team members.
Once the mold has been prepared, these same 7-10 members will have to prep the flax fiber and foam core to be laid up and laminated. 1-2 members will use drawing software and the CNC fabric cutter in the composites shop to cut out layers of flax fiber from a roll while conserving as much fiber as possible. 3-4 members will then have to prepare the mold for resin infusion. This is a tedious process that will take several hours. It consists of laying up the layers of fiber and core material and applying vacuum bagging materials and infusion tubing. Once members have applied a vacuum and decided that the system is leak-free, they will mix the epoxy resin and begin the infusion process. The infusion process itself will take less than an hour but the part will then need to cure under a vacuum for about 48 hours to reach maximum strength and durability. This process will have to be completed for the top and bottom halves of the hull, the hatch, and to join the halves of the hull together.
After the lamination process has been finished, all members will still have to work on sanding the exterior of the hull to remove scribe lines, blemishes, and prepare the hull surface for painting. This entire process is expected to take about 3 months to complete, starting at the end of winter quarter and ending near the end of spring quarter. But, even after this process has been completed, this hull will continue to be the centerpiece of our work on the Human Powered Submarine team for the subsequent two years. All of the rest of the members of our team will work to integrate a drivetrain, control system, propulsion system, electronics system, and safety system into this hull.
Covid-19 has made it more difficult for our team to access the composites lab, but many of our members are already certified as critical personnel, and may access the shop at any time while following strict guidelines. Those who do not currently have shop access will still be vital towards project Orca, so we plan to begin the process with as much involvement through research as possible and continue our work as soon as we can have an adequate number of members working in person.
Education & Outreach:
A human powered submarine is not a common sight. This makes our submarine one of the centerpoints of attention at University of Washington events such as the Dawg Days RSO Fair, Engineering Launch, Discovery Days, and Introduce a Girl to Engineering. At each of these events our submarine is on full display for all University of Washington students to admire. Our team members occupy booths and tents where onlookers can come ask questions and learn more about the materials and development of our submarine. Specifically at engineering discovery days and Introduce a Girl to Engineering, we instill the idea of engineering for sustainability in the minds of elementary, middle, and high school students who come to learn about STEM at the University of Washington.
In addition, we have made it our goal to document the sustainable design and manufacturing processes of our hull to share with the other engineering teams at the UW. This will also be a major talking point at our International competition where we will discuss our sustainable efforts with the judges and other competitors. There are many other student led clubs and projects that incorporate the use of polymer reinforced composites on various scales. These teams almost solely use carbon fiber and fiberglass as reinforcement. We believe that by reaching out to these teams and educating them on our sustainable endeavors, we can help urge them to shift their practices towards a more environmentally friendly direction. Once our hull has been successfully completed, we plan to reach out to these teams with more specific and meaningful information.
Covid-19 has made planning education and outreach more difficult than normal. There is so much uncertainty that we are still unsure what we will and will not be able to do. Until times are more certain, our social media platforms and newsletters will be vital to informing people in and around the University Washington about our sustainable endeavours.
- Energy Use
The Human Powered Submarine team consists of a dedicated group of about 50 undergraduate students in various engineering majors. We are supported by a plethora of motivated faculty and passionate sponsors that encourage us to push boundaries and forge ahead. Over the next several years, our team members will design, build, redesign and rebuild hull componentry and features in preparation for a competition each year. We expect to use this hull for at least the 2021-2022 and 2022-2023 competitions seasons. Although naturally biodegradable, the fiber will not break down inside the hull while in its resin matrix. Only minor exterior touch ups may be necessary. Future years leads will oversee the development and path of submarine subsystems and hull maintenance. With access to some of the most advanced labs, shops, and workspaces in university engineering we will maintain and improve the integrity of the hull. We also have multiple sources of funding from our team members, sponsors, and engineering departments. This gives us the freedom and peace of mind to explore and implement new features and processes that other teams may not have the ability to do.
At the end of this hull’s life, the team will look into next steps for the hull. They may decide to put it into use again, display it, auction it for team funding, or research ways to break down the resin matrix, obtain, and reuse the original flax fiber. Alternatively, at this point the team could decide to pursue a new innovation or hull material or go back to using carbon fiber reinforced composites. If the team decides to use flax fiber again, they may pursue additional funding from the CSF, sponsorship from the sourcing companies, or even buy the material outright. Much depends on the team interests and budget at this point in the future.
In years past, our engineering team has almost always used a carbon fiber reinforced polymer layup process to manufacture our submarine hull. The materials in this process pollute the environment and increase the amount of carbon dioxide being released into the atmosphere. The production of carbon fiber releases a significant amount of greenhouse gasses and it is about 14 times as energy intensive as steel manufacturing, for comparison. In addition, the epoxy resins and foam cores normally used in the manufacturing process are non-recyclable and create a lot of waste.
This year, to mitigate our environmental impact, we have decided to manufacture our hull using environmentally sustainable materials that still retain our strict material strength requirements. We started by researching natural fibers, recycled carbon fiber, and dissolvable resin matrices and ultimately decided to use natural flax fiber.
Our research into natural fibers was initially disappointing but we ended up finding a perfect fit. Preliminary research pointed towards difficulty obtaining and manufacturing using natural fibers. Natural fibers have the tendency to soak up moisture more than carbon fibers and fiberglass. Since we are building a submarine, this initially turned us away. But after further research, we found a company called Bcomp in Europe who manufacture flax fiber called Amplitex. Their fiber has been used in many applications throughout Europe ranging from racing boat hulls to Formula 1 composite parts. The flax fiber offered the strength and stiffness we needed and was already proven to work well in industry.
After our research and calculations, the team determined that the flax fiber was our best option in terms of strength, sustainability, and availability. In addition, through our sustainability research and contact with various sponsors and composites suppliers we found recycled foam to use as a core material at no additional monetary cost, further increasing our sustainability.
Explain how the impacts will be measured:
Project Orca aims to reduce the carbon emissions associated with using carbon fiber while involving and educating our team members about sustainable solutions. Calculations had to be performed to make sure that the carbon dioxide emissions from producing carbon fiber would still be significantly more than the emissions from shipping the flax fiber from Europe to the US on a cargo ship. Team members compared flax and carbon fiber carbon dioxide emissions by assuming negligible flax production emissions and negligible carbon fiber shipping emissions. Using formulas for carbon fiber production and electricity use emissions, as well as a formula for fuel consumption to quantify cargo shipping emissions, we found that carbon fiber production creates about 100,000 times the carbon emissions as shipping flax fiber for the same mass. This is so large because the flax fiber is such a small percentage of the max load carried by the cargo ship.
Millions of college engineering students are graduating each year and entering the workforce in all different industries and capacities. At a time where our environment is at a critical tipping point, it is more important than ever to educate our younger generations in the area of sustainability. It is important that new engineers enter the workforce conscious of their environmental responsibility and more prepared than ever to innovate old and environmentally detrimental processes. Our impact is measured by our reduction in carbon emissions and the idea of engineering for sustainability that we can instill both on our team and in the engineers around us. We believe that metrics we can use to track this include the number of submarine showcase events we have attended, number of teams we have reached out to and educated about sustainable engineering, and number of members we have graduated into the engineering workforce.
This funding request is a: Grant
If this is a loan, what is the estimated payback period?:
|Cost per Item
|Biax 45 Flax 63.5m Roll
|2x2T Flax 50m Roll
|Estimated Completion Date
|Mold Surface Preparation
|March 19, 2021
|Fabric and Foam Core Preparation
|April 1, 2021
|1 day per infusion (at least 3 necessary)
|June 1, 2021
|Resin Infusion and Curing
|2-3 days per infusion
|June 1, 2021
|June 18, 2021