Section I: Introduction Please select one topic from the ideas in Section III below. This is a microfabrication or nanomaterials project that will require engineering design skills. You will need to be familiar with the nano/micro fabrication processes needed to manufacture all components of your project, and you will need to describe the process sequence(s) for producing each component. All projects listed in Section III provide some form of technical support to the HAAMER project. This project involves a high-altitude balloon system that La Trobe University is developing. If you are unfamiliar with the HAAMER Project, please refer to an overview that will be posted on the LMS site in the EMS5NME/Group Project folder. How You Should Approach This Project: This project will teach you to: (1) identify the challenges associated with your project topic (i.e. define the problem), (2) search in the literature for what others have done, (3) use creativity and brainstorming to find your own solutions, (4) evaluate your solutions and perform calculations to see if your solution should work, and then (5) further develop this solution, adding important details, e.g. dimensions, tolerances, materials, CAD drawings, etc. It is assumed that at least one member of your team is capable of creating computergenerated engineering drawings. Finally, during step (6), you will communicate this selected design and summarize your work by generating a group project report. In other words, you will be following the engineering design process given below (Fig. 1), from the onset to the end of the project, while skipping the testing and iteration steps (for lack of time to carry these out). Fig. 1: Elements of the Engineering Design Process (Source: youtube.com) Section II: Project Requirements Things you will need to complete for your project: • Form a team of at most three individuals in LMS. If you don’t know anyone, the teaching assistant(s) will help to team you up. • Arrange how you will work electronically with these individuals–without any direct personal contact (exchange phone numbers, emails, arrange Zoom meeting IDs, etc.). If you can’t contact these individuals, please email the teaching assistants. • Divide the design engineering and report writing tasks evenly amongst yourselves, so no one person has too much to do. • Meet electronically for each phase of the design project (each step in Fig. 1). • Brainstorm your collective ideas, document them, analyse them, and choose the winning design. • Justify your choice for this solution by providing calculations of its anticipated performance. • Put additional details into your design choice. This should include engineering drawings with dimensions, tolerances, and materials for each component. • Provide detailed CAD drawings with dimensions for each element (your own work). • Explain how you would minimize mass by microfabricating each component. • Provide a “workable process sequence” to fabricate each component, or, if nanomaterials, the processes required to synthesize these materials. • Determine the final assembled mass of your system. • Write a final report, as described below. Each individual is required to write at least two sections of the final report. The author’s name must appear in the header of the pages that he/she wrote. The final report must be uploaded as a single document into LMS by one group member. 50% of your report grade will be based on your individual contribution, based on what we see written by you (no name, no credit). Your proposed solution must meet the performance criteria provided in Section III, while minimizing the mass (or cost) of your solution. You will be graded on how well you minimize mass (or cost) yet achieve the performance goal. You will also be graded on the appropriate use of microfabrication processing sequences to fabricate your system components. Depending on your project, a few components may be exempt from the nano/micro fabrication requirement, as determined by Prof. Maxwell. Please check for proper English grammar and word usage. Final Report: You will need to write a final report to communicate your solution. It should be in the following format, with the given bolded headings: 1. Introduction to the project/problem (1) page: Assume we know about the HAAMER project, but we need to be told what problem(s) you are solving for this project. 2. Identify Engineering Constraints to your solution (1/2 page): Tell us what the boundary conditions are, limits on the design, what performance your solution should have, and what the priorities or criteria for selecting your design are. 3. Potential Design Solutions: Provide ≥3 possible solutions
3. High-altitude Micro-actuated Wind Vane Arrays: Assuming wind is flowing past the balloon, it should be possible to control orientation of the sphere by using wind vane arrays (similar to a windmill). With several vane arrays around the sphere, multiple wind directions can be accommodated. By opening/closing some vane flappers in an array, the wind drag at any array can be decreased/increased. The open cross section facing the wind determines the wind drag; this force can be used to control the sphere’s orientation. A related example can be seen in: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.662.8684&rep=rep1&type=pdf Assumptions/Design Limits: –Assume relative constant wind velocities flowing past the wind vane arrays at 2.2 m/s. –Assume 3+ separate units will be needed for stabilization. –All components of the array must be nano/micro fabricated. –Mass must be determined and minimized! –Look up examples of various microactuators in the literature to move the vane flappers. Performance Criteria: –Your design must be able to stop the rotation of a floating 3kg sphere that is 10cm in diameter within 3 minutes. The sphere is initially rotating about a vertical axis at 0.05 Hz (1/20th of a rotation per second). –Provide calculations showing that the drag force you generate is sufficient to stop the sphere from rotating in 3 min. Scale your array to achieve this. –Provide energy calculations showing how much stored energy (J) will be needed to control the array flappers and continually stop such a sphere from moving over the course of an hour (once it stops, the scenario resets to the initial rotational velocity). –Mass must be minimized! Remove all unnecessary mass.