Don’t Leave it to Beaver A Hydroelectric Dam Engineering Teaching Kit

Don’t Leave it to Beaver A Hydroelectric Dam Engineering Teaching Kit The University of Virginia School of Engineering and Applied Sciences Michael Underhill Michael San Antonio Colin O’Brien Jason Kaplan Point of Contact: Michael San Antonio mts2y@virginia.edu Concepts: ©VMSEEI Hydrostatic Pressure, Potential and Kinetic Energy, Simple Machines, Electricity ©VMSEEI TABLE OF CONTENTS Executive Summary _2 Applicable SOL’s _3 Materials Needed _4 Unit Overview Unit Preparation _7 Day 1: Intro to Hydroelectric Dams and Energy Lesson Plan _8 Worksheet: Hydrostatic Pressure & Water Flow 12 Worksheet: Energy 13 Day 2: Turbines and Mechanical Energy _14 Lesson Plan 14 Worksheet: Torque _16 Day 3: Electricity and Magnetism _17 Lesson Plan 17 Worksheet: Electricity and Magnetism Exercise 20 Worksheet: Motors and Generators 21 Day 4: Integration and Testing _22 Lesson Plan 22 Worksheet: Initial Hydroelectric System Design 24 Worksheet: Expectations _25 Day 5: Competition 26 Lesson Plan 26 Worksheet: Lessons Learned 28 Citations 29 ©VMSEEI Executive Summary The mission of the Don’t Leave it to Beaver Engineering Teaching Kit is to educate middle school students on some major concepts in engineering and science in the inner workings of hydroelectric dams While we are primarily concerned with the technical and engineering aspects of these systems, the broader context of “clean” energy is also an idea that this teaching kit drives home Some of the main concepts included in this kit are potential, kinetic, and electrical energy and the relationships between them Torque, motors/generators, and water flow are also key components of our lesson plan Considering the present energy crisis and issues of global warming facing the world, renewable and clean energy is an extremely important topic Hydroelectric power is just one of a number of renewable solutions which include solar, wind, and geothermal power as well Throughout our process, students will see many demos, build various parts of the hydroelectric system, and make crucial decisions for their final product They will learn to work as a team and fully experience the engineering design process This process includes: problem identification, brainstorming, design, construction, testing, and improvement Studies have shown that hands-on learning is extremely effective for engineering education Younger students are more impressionable and develop constructs that will affect how they will learn in the future Therefore, it is crucial to instill an early interest in engineering through fun and interactive activities Our goal is to form the fundamental building blocks they need to solve critical problems of the future The entire lesson plan is centered around the competition on the fifth day The concepts taught on the first few days are integrated into their final design The students will select a generator, build a turbine and shaft structure, and route water incorporating those elements into a pre-built structure to create a complete hydroelectric dam within a tank The teams will compete to produce the most electrical power While the final results are important, we want the students to be able to explain their decision process and walk away from this experience with a greater interest in engineering ©VMSEEI Applicable SOL’s PS.1 The student will plan and conduct investigations in which a) chemicals and equipment are used safely b) length, mass, volume, density, temperature, weight, and force are accurately measured and reported using metric units (SI) c) conversions are made among metric units, applying appropriate prefixes e) numbers are expressed in scientific notation where appropriate g) independent and dependent variables, constants, controls, and repeated trials are identified k) valid conclusions are made after analyzing data i) research methods are used to investigate practical problems and questions n) an understanding of the nature of science is developed and reinforced PS.6 The student will investigate and understand states and forms of energy and how energy is transferred and transformed Key concepts include a) potential and kinetic energy b) mechanical, chemical, and electrical energy PS.10 The student will investigate and understand scientific principles and technological applications of work, force, and motion Key concepts include a) speed, velocity, and acceleration b) Newton’s laws of motion c) work, force, mechanical advantage, efficiency, and power d) applications (simple machines, compound machines, powered vehicles, rockets, and restraining devices) PS.11 The student will investigate and understand basic principles of electricity and magnetism Key concepts include: a) static electricity, current electricity, and circuits b) magnetic fields and electromagnets c) motors and generators ©VMSEEI Materials Needed Material liter soda bottle (2) Pitcher for pouring water Tank Ball String Quantity 1 1 types/group set/group set/group box Location Common Common Whatever is available Common Common 1/group 1/group Set of 12 coils Common Multi-Meter Test Leads Multi-meters DC Brush motors (3 different choices) Batteries (various types) Wood (2x4, for dam support structure) Garden hose (or other access to water) Plywood (Dam Construction) Corks Plastic Spoon heads (various sizes) Plastic Knives (various sizes) Popsicle sticks Balsa Wood Glue (waterproof) Scissors Permanent bar magnets Coiled wire Rubber Stoppers (3 different sizes) Legos (shafts) Exacto Knives Wood Glue Hot Melt Glue Hose of various sizes Duct Tape Price/qty Manufacturer Part # www.lakeshorelearning.com Allied Electronics Website $7.80 $30.88/100 ft Alpha Wire 1/group Allied Electronics Website Allied Electronics Website $4.56/cable $29.24 each 3051-BK005 BU-1031-A24-2 DM7C per team Allied Electronics Website $16.77/motor sheet of each size Available at hardware stores $20 Available at hardware stores $1.00 set of 13 Available on amazon.com $6 Mueller Amprobe Parvalux Motors 52310 ©VMSEEI Unit Overview The first three days of this lesson plan are devoted to teaching a number of valuable concepts related to hydroelectric power generation Activities and demos are used throughout these days to further enhance the ideas and allow students to learn more effectively The fourth day is primarily a construction and integration class where students will have the opportunity to apply their new knowledge and work together in a team environment The fifth and final day is reserved for the team competition of their hydroelectric systems and a general wrap up of the major ideas and lessons learned Day 1: Introduction to Hydroelectric Dams and Energy Preliminary Lesson Summary: Students will be introduced to hydroelectric dams by showing them some famous dams and explaining why they are important Next, hydrostatic pressure and the various forms of energy will be discussed using demos and worksheets The day will conclude with a demo of the example dam and a quick discussion of safety Objectives:  Introduce students to hydroelectric dams and why they are important  Educate students on the principle of hydrostatic pressure and how it relates to dam structures, geometries, and power generation  Educate students on three major forms of energy: potential, kinetic, electrical  Address safety issues, especially with regards to water and electricity Day 2: Turbines and Mechanical Energy Preliminary Lesson Summary: Teams will be introduced to general examples of turbines and their basic principles will be covered Demonstrations will be used to explain the concept of torque and the methods to maximize it As students gain an understanding of mechanical energy in turbines they will be introduced to their given materials and individually draw up possible designs for a turbine, giving them a chance to apply these principles After some discussion team members will compare designs and then collaborate to build one turbine for their team, which will later be used during their final competition Objectives:  Introduce students to turbines and how they are used in hydroelectric power generation  Describe principles of torque and maximization  Encourage planning, design, and problem solving in the building process  Student teams build their turbines for use in their hydroelectric systems ©VMSEEI Day 3: Electricity and Magnetism Preliminary Lesson Summary: Teams will be introduced to the concepts of electricity and magnetism and how they are used to produce power Teams will learn how to perform some basic measurements on a vital electronic instrument called a multi-meter They will then use the multi-meter to explore the functions of generators and motors and how they are different They will conclude the lesson by analyzing a set of generators and will choose the best one to incorporate into their turbine design from Day Objectives:  Explore fundamental concepts of electricity and magnetism  Understand how motors and generators work and know how they are different  Understand basic circuit concepts  Learn the basics of how to produce electrical power from mechanical work Day 4: Integration and Testing Preliminary Lesson Summary: Today consists mostly of allowing the students to work together freely in their teams to complete their hydroelectric systems Teams must integrate their parts made/selected from the first three days of this project and determine how best to direct the flow of water to their turbine Additionally, as teams are ready, they may test their systems within the tank using water and make adjustments as necessary Objectives:  Students integrate turbines and generators from days 2-3  Groups determine how best to funnel the water from the dam  Teams complete their hydroelectric systems  Students test systems and make adjustments as necessary Day 5: Competition Preliminary Lesson Summary: Today is the day of the grand competition where students’ hopes and dreams will be either fulfilled or crushed in a climax of excitement, but either way they will be learning! Each of the teams will have an opportunity to test their systems and attempt to generate the most power Afterwards, the lessons learned will be summarized and stressed for better retention Objectives:  Every team has the opportunity to test their hydroelectric system  Students learn the concepts covered in days 1-4 by seeing them in action ©VMSEEI   All major concepts are reviewed afterwards Students provide feedback on their team, the competition, and lessons learned ©VMSEEI Unit Preparation ©VMSEEI Turbines: Force of water causes rotational motion of turbine Begin to question students on concept of torque Discussion of Torque (10 min): Discuss what causes object to rotate Go through worksheet questions Introduce concept of torque Have students attempt opening door from different points as in the Torque worksheet Ask students to explain through torque definition, why door is easier to open from outside (ie at the knob) τ = Force x Moment Arm Demonstration with See-Saw Balance weights on opposite side of fulcrum Show that a smaller weight further from center, can balance with larger weight closer in Reinforce torque concepts in discussion for building their turbines Here’s a link with a refresher on torque: http://en.wikipedia.org/wiki/Torque Introduce Student Design and Individual Drawing (5 min): Show students the materials they will be given Ask them to draw out basic designs Allow a few minutes for drawing Building (20 min): After a discussion on safety (knives, scissors, crazy glue), allow students to join into their groups Promote discussion amongst groups in deciding on plans Distribute materials to each group and then ask them to draw their group plan for a turbine Allow time for students to build while providing advice Encourage groups to run water over their turbine during building process and then improve their design if necessary Wrap Up (5 min): Teacher will first ask class what they learned during this lesson Then the teacher will inform students of upcoming lesson plans and concepts ©VMSEEI 17 Name Date _ Class _ Torque Door Example: Which position will the door be easiest to open at? (Circle one and explain) A B C Doesn’t Matter Which direction will the see-saw fall? (Circle one and explain) Left ©VMSEEI Right Neither 18 Day 3: Electricity and Magnetism Extended Lesson Summary: Teacher will introduce students to the basics of electricity and magnetism and how they are two key phenomena used to produce electrical power from mechanical work Today’s lesson will begin with teaching the class a little about circuits and how electrons flow to produce electric current The class will then divide into teams and will learn how to operate a multi-meter They will explore that when there is electricity flowing through wire, magnetic fields are produced and vice versa If there is time, the students will get to see the inner workings of a generator and be able to explain how they work The conclusion of the lesson will be for the teams to analyze a set of generators to determine which one will produce the most power for their hydroelectric system Objectives:  Explore fundamental concepts of electricity and magnetism  Understand how motors and generators work and know how they are different  Understand basic circuit concepts  Learn how to produce electrical power from mechanical work Virginia SOL’s:  PS  PS 6b  PS.11 Materials: Permanent magnets Electrical cables (For connecting multi-meters and generators) Coiled wire Alligator clips Banana plugs Multi-meters DC Brush motors (3 per team) Batteries (various types) Worksheets: Electricity and Magnetism, Motors and Generators Teacher Prep (20 min): Make photocopies of two worksheets (one copy per student) Assemble materials for each activity and distribute for each group Detailed In Class Lesson Plan: Introduction to Electricity and Magnetism (5 min): Students will be presented a short power point (projector slides if necessary) of electric circuits They will be able to understand that closed loops are necessary for ©VMSEEI 19 current to flow and that voltage is the driving factor that produces current They will also be shown some slides dealing with magnetism and some basic concepts such as poles and magnetic fields influencing the attraction and repulsion of objects Finally, for safety measures the teacher will explain why it’s important that they not directly attach the positive end of the battery to the negative end (it will get very hot!) Also, the teacher should stress that students not touch the two probes of the multi-meter together (may break depending on what it’s measuring!) Here are some links with refreshers on electricity and magnetism concepts: http://science.howstuffworks.com/electricity.htm http://science.howstuffworks.com/electromagnet.htm First activity (20 min): Teacher will show teams how to use a multi-meter and give them a worksheet to fill out to evaluate what they know about it The teacher will have them measure the voltage drop across a standard battery If there’s time, the teacher may want to ask them to measure the current on their own It would be a trick question because the current flow would be infinite because there would be no resistance in the circuit This will get them to think about the concept of resistance in closed-loop circuits Here is a link to a site with directions on how to use the digital multi-meter: http://www.ehow.com/how_4499779_read-digital-multimeter.html To illustrate the concept that allows generators to convert mechanical work into electricity, have the teams take their magnet and move it back and forth through the coiled wire The teacher will have them measure the voltage produced by these motions and let them figure out what motions and factors produce the most voltage < We will include a picture demonstrating this activity here> If there is time, show teams the inside of a broken motor/generator Show them where the magnets and coil are and explain how what goes on inside the generator is directly related to the experiment in the preceding paragraph Second Activity (20 min): Teacher will explain the differences between generators and motors Motors transform electrical energy into mechanical work while generators the opposite The teacher will then pass out a set of generators for each team Each generator in the set should have a different gearing ratio making some more difficult to turn than others Each team will complete the worksheet corresponding to the activity with three generators The teacher should inform the teams that it will be more difficult to turn the shaft of the generator at the same speed while measuring the current Also, the teacher should show the teams that Power = Voltage x Current to fill in the last column In the end, each team will pick the generator from their set to use on Day when they put together the entire hydroelectric system ©VMSEEI 20 Wrap Up (5 min): Teacher will first ask class what they learned during this lesson Then the teacher will inform students of plan for tomorrow ©VMSEEI 21 Name Date _ Class _ Electricity and Magnetism Exercise On the circuit diagrams on the left, indicate what direction the current is flowing Draw the magnetic field lines for the magnet on the right Bulb N S Use the multi-meter to measure the voltage drop across the battery Voltage of the battery read from the multi-meter: V Which of the following greatly influenced the voltage you obtained from moving the magnet around the coil? A) Distance of magnet from coil B) Speed of magnet C) Orientation of magnet D) Number of Coils ©VMSEEI 22 Name Date _ Class _ Motors and Generators Draw an arrow in between the electrical and mechanical blocks showing the direction of energy transfer for a generator and a motor Motor Electrical Generator Mechanical Electrical Mechanical Fill in the table while following the steps below At the end of this exercise, decide which of the three generators will work the best for your team’s turbine Determine the following for all Generators using the multi-meter:  Hook up multi-meter to the wires coming out of the generator (Remember: Red is Positive, and Black is Negative or Ground)  Turn the shaft of the generator until you can get it to spin at a comfortable speed and maintain it (Note: Turn at this same speed for all generators) Generator # Difficulty to Move Voltage (V) Current (A) Power (W) ©VMSEEI 23 Day 4: Integration and Testing Extended Lesson Summary: At the beginning of class there will be a very short recap of what the students have learned in the first three days and how it all fits together The rest of the class consists of allowing the students to work together freely in their teams to complete their hydroelectric systems Teams must integrate their parts made/selected from the first three days of this project and determine how best to direct the flow of water to their turbine Additionally, as teams are ready they may test their systems within the tank using water and make adjustments as they deem necessary Objectives:  Students integrate parts from days 1-3  Groups determine how best to funnel the water from the dam  Teams complete their hydroelectric systems  Students test systems and make adjustments as necessary Virginia SOL’s: PS.1 a,k,i,n PS.6 a,b PS.10 a,c,d Materials: Tank with pre-constructed structure Access to water Several boards with holes cut out Rubber Stoppers Legos Balsa Wood Exacto Knives Wood Glue Hot Melt Glue Straws Hoses of various sizes Materials from days 1-3 Worksheets: Initial Hydroelectric System Design, Expectations (One per student) Teacher Prep (20 min) Assuming the boards are already made Make photocopies of two worksheets Lay out all materials Prepare tank and water source for testing ©VMSEEI 24 Detailed In Class Lesson Plan: Introduction (5 min) Present a brief recap of what students have made and done over the last three days Explain to the students that today is when everything comes together Review the basics of how a hydroelectric dam works using the picture below Team Construction and Testing (40min) Break class back up into teams and have them work on completing their hydroelectric system This involves connecting the turbine and motor through a shaft system and also includes deciding on where to release water and use tubes, ducts, etc to route water from dam to turbine Actively walk around and aid students with construction Try not to answer too many of the students’ questions; remember there is no right or wrong way to this project As students complete their systems, allow them to test in the tank and make observations and adjustments as they wish Also they are to fill out the first worksheet by the end of class Wrap-up (5min) Briefly cover the plan for the competition on Day Be sure to have the students come ready to go for the completion and, if desired, provide information on additional times that they may work on their hydroelectric systems (ie Lunch time) Assign Expectations worksheet as homework ©VMSEEI 25 Name Date _ Class _ Initial Hydroelectric System Design In the space provided, make a rough sketch of your team’s hydroelectric system Label the Turbine, Generator, and the path the water should take Explain why you chose your design Some questions you might discuss: Why did you orient the turbine as you did? Why did you choose that hole on the dam for the water flow? Why did you link the turbine shaft and generator as you did? ©VMSEEI 26 Name Date _ Class _ Expectations What are your expectations for how your hydroelectric system will perform? Explain your reasons What would you change if you had another day to work on your system? If your team had an opportunity to test your dam, what observations did you make as to how your hydroelectric system performed? What adjustments (if any) did you make to your system after testing? At this point, without knowing how your hydroelectric system performs, are you happy with your team’s design? If you could it all over again what would you differently? Why? ©VMSEEI 27 Day 5: Competition Extended Lesson Summary: Today is the day of the grand competition where students’ hopes and dreams will be either fulfilled or crushed in a climax of excitement, but either way they will be learning! Each of the teams will have an opportunity to test their systems and attempt to generate the most power Afterwards, the lessons learned will be summarized and stressed for better retention Objectives:  Every team has the opportunity to test their hydroelectric system  Students learn the concepts covered in days 1-4 by seeing them in action  All major concepts are reviewed afterwards  Students provide feedback on their team, the competition, and lessons learned Virginia SOL’s: Materials: Tank to hold dams, water, and hydroelectric system Pre-constructed support structure and testing dam Access to water Several boards with holes cut out Rubber Stoppers Duct Tape Multi-meter All construction materials from Days 1-3 for last minute repairs Worksheets: Lessons Learned (One per student) Teacher Prep (20 min) Prepare the tank in an area with access to water and a drain, and in a location easily viewable by the students Be sure to have the tank situated properly before filling with water as it will likely be too heavy to move once this is done Place the dam against the support structure inside the tank Plug all holes of the dam and seal the dam against the bottom and sides of the tank Fill the water side of the tank with water before class, allowing some time to fix any leaks that may occur Open one hole and test to make sure that the drain works properly and that your hose to refill the water side is functional (may use a bucket instead) Finally, make copies of the Lessons Learned Worksheet for the class Detailed In Class Lesson Plan: Introduction (5 min) Quickly recap the plan of the day and decide on the first few groups to go Tell teams that they may make any changes and last minute updates as other teams are tested Additionally, tell the teams that, if time permits, they may retest their hydroelectric ©VMSEEI 28 systems if something goes wrong the first time, but only after all the teams have had a chance to go Competition (40 min) Conduct the competition by testing the teams’ systems one at a time Place the system to be tested within the tank against the support structure and dam with all holes currently closed so no water is flowing Be sure to open the drain on the dry side of the dam and have the water exiting the tank to keep this side relatively dry Teams will each have minutes to set up their system When ready, the team will remove the stopper that they wish to allow water to flow Each test will be minutes in length, and the team will get a score based on the maximum power generated during this time Once the team is done, replace the stopper to close the water flow The team will remove their system and another team will begin their setup Wrap-up (5min) Congratulate all teams on their performance Announce the winner of the competition! Pass out the Lessons Learned Worksheet either for homework or to fill out at the end of class as time permits Make any closing remarks that you wish ©VMSEEI 29 Name Date _ Class _ Lessons Learned How did your hydroelectric system perform during the competition? Now that you have seen how your team’s hydroelectric system operated, what changes would you make if you could it again? What did you learn from this project? Did your team work well together? What could be improved in the future? Would you like to work with these people again on another project? Why or why not? How could this project be improved in the future? ©VMSEEI 30 Citations Beaver on Cover Page: http://ci.marysville.wa.us/PublicWorks/swm/docs/beaver.htm Dam on Cover Page: http://www.hydropowerusa.com/ Hoover Dam on Page 7: http://gocalifornia.about.com/bl_nvhdamphoto_dam.htm Schematic of Hydroelectric Dam on Page 20: http://www.window.state.tx.us/specialrpt/energy/renewable/hydro.php ©VMSEEI 31 ... Generators Draw an arrow in between the electrical and mechanical blocks showing the direction of energy transfer for a generator and a motor Motor Electrical Generator Mechanical Electrical Mechanical... Learned (One per student) Teacher Prep (20 min) Prepare the tank in an area with access to water and a drain, and in a location easily viewable by the students Be sure to have the tank situated... with water as it will likely be too heavy to move once this is done Place the dam against the support structure inside the tank Plug all holes of the dam and seal the dam against the bottom and