Sail Through Engineering Post-Workshop Activity Thank you for participating in the Sail Through Engineering Workshop. We hope you and your students enjoyed your time at the MIT Museum. This post-workshop activity is designed to help students continue the iterative engineering process. If students would like to continue to explore nautical objects including half-hull models, boat designs, and navigational charts, the MIT Museum s Nautical Collection can now be accessed online with new and expanded content: https://mitmuseum.mit.edu/explore/collections. Materials Sail Through Engineering worksheets from the MIT Museum One post-activity worksheet per pair of students Pencils Scissors Plastic straws Cardstock Hot glue Several varieties of tape Computers (with access to the internet) Printer MIT Museum Boat Cross-Section Online Application: http://webmuseum.mit.edu/herreshoff/ Fluid Dynamic Simulator: https://physics.weber.edu/schroeder/fluids/ Tubs of water Newton-meter Gram cubes Setup 1. Set up a supply station with hot glue, cardstock, and tape. 2. Fill 1-4 tubs with water for testing of the new boat models. Activity 1. Hand out one post-activity worksheet per pair of students. Make sure that each group has access to the internet on a computer or other device. 2. Students should have the worksheets from the MIT Museum s Sail Through Engineering workshop with them. 3. Review the engineering cycle with the students. Ask them to describe how they carried out each step during the workshop at the MIT Museum. 4. Reiterate the importance of the original challenge question and definition of the criteria of success. Students should write down their original challenge (boat type) and criteria for success on the post-workshop worksheet. 5. Students will then work through the post-workshop worksheet in order to improve upon their original boat hull design from the workshop. 1
Name: Date: Sail Through Engineering Post-Workshop Activity Worksheet Engineering is an iterative process. This means that solutions to problems are tested and then modified based on data collected in experiments. The following procedure will guide you through the process of using the data you collected at the MIT Museum to improve upon your boat design. 1. Look at your criteria for success and data collected during the workshop at the MIT Museum. In what ways was your boat successful? Support your answer using data from your experiments. 2. Look at your criteria for success and data collected during the workshop. In what ways was your boat not successful? Support your answer using data from your experiments. 2
3. In order to design the next version of your boat, it is important to research some of the ways that other people have solved similar problems. The following chart will help you to organize your research. Use three different resources to help you design the next version of your boat hull. (Resources can include websites, books, boating experts, and more.) List what you learned from each source: Source Number Source Name What did you learn? 1. 2. 3. 4. Based on your background research, sketch a picture of your next boat hull design. Include a side view and a top-down view. 5. Before you build your next boat hull model, you will test the design using a computer simulation. What is an advantage of using a computer simulation before building a physical prototype? 3
6. Go the following website: https://physics.weber.edu/schroeder/fluids/ This computer simulation lets you draw a top-down view of your boat and observe how water will flow around it. The simulation will also let you study the force of drag. Drag is the force with which the water pushes backwards on your boat as it moves. This simulation shows fluid flowing from left to right as viewed from above. (Initially, a straight barrier is shown.) Click start to see how the barrier diverts the fluid around it. Change the shape of the barrier by pressing pause. Click clear barriers and then click and drag on the green simulation box to draw your boat. Click the checkbox next to Show: Force on barriers to show the force exerted by the fluid on your boat hull. 7. The force on the barrier tells us about drag. Using the simulation for reference, circle increase or decrease in the following sentences to complete each statement: An increase in surface area (the amount of the boat hull exposed to the water in its direction of movement) would increase/decrease drag. An increase in the boat s speed would increase/decrease drag. If the width of a boat is decreased, the drag would increase/decrease. However, stability of the boat might increase/decrease. 8. After trying multiple boat designs in the simulation, draw your final design below. Briefly describe why you chose this design. 4
9. Complete the table below by describing up to three changes that you will make to your first boat model regarding size, drag, capacity, or other factors: What will you change from your first boat model? Why did you make this change? 9. Based on your full boat drawing, draw a half hull model below. (This should be a side view of your new boat design.) 10. In your sketch, draw five vertical lines across the half hull. These represent the slices that you will use to build the boat s overall shape. Label the slices 1-5. 5
11. Go to the following link in order to access the CAD software that you used during the MIT Museum workshop: http://webmuseum.mit.edu/herreshoff/ - Change your x and y values in order to create the cross-sections of the new boat hull that you drew in question #9. -When finished, export and print the file that has been downloaded. 12. Follow the directions below in order to build your new boat hull model from the printed cross-sections. -Use scissors to cut out your five slices. -Trace your slices onto a piece of cardstock. -Cut out the cardstock pieces (Picture A). -Cut a drinking straw into four equal pieces. -Use hot glue to attach the straws to your slices (Picture B). -Glue plastic wrap to the bottom of your boat for waterproofing (Picture C). -Select the type of tape that you are going to use for the outside of your hull and seal your boat hull with the material (Picture D). A B C D 6
13. Carry out the four tests with your boat that you did in the workshop at the MIT Museum and report your data below. Test A: Tracking Test Place your boat at one end of the water tank. Gently push your boat with enough force so that it will make it to the other side of the tank. Repeat the experiment at least 5 times in order to determine a consistent pattern: does the boat move in a straight line, turn, spin, or something else? Test B: Drag Test Attach a Newton-meter to the front of your boat and pull it gently through the water at multiple speeds. Record the force that it took to pull the boat. Test C: Weight Capacity Test Add weights to your boat until water begins to enter the top of your boat. Remove the weights and record the total weight capacity of your boat. Test D: Stability Test Place your boat in the water and wait until it stops rocking. Gently create a wave that hits the side of your boat. Repeat with waves from the front and back of the boat. Describe how your boat responded: did it stay upright, tilt very far to one side, get pushed up against the side of the container? 7
14. Design a new experiment to test your boat. a. What question will this experiment attempt to answer? b. Write a step by step procedure for your experiment. c. Record your experimental data below. 15. Look back to your original challenge and criteria for success. In what ways is your new boat better than your previous boat? 16. If you carried out another iteration of boat design, what would you change based on your new data? Now that you have run through the engineering design process, see if you can engineer solutions to these other nautical challenges: -Design a propulsion system for your boat -Design a method of steering your boat 8