Presentation on theme: "Engineering Education-EngE 1024 December 1, 2009 Created by: Erin Crede Introduction to Experimental Design and Testing."— Presentation transcript:
Engineering Education-EngE 1024 December 1, 2009 Created by: Erin Crede Introduction to Experimental Design and Testing
Presentation Outline Learning Objectives Pre-Class Assignment In Class Activity Materials Logbook Competition! Sample Results Out of Class Assignment Possible Test Questions
Learning Objectives 1.Introduce students to experiment logbook preparation and use. 2.Introduce students to gliding flight, specifically performance calculations. 3.Construct, test, and evaluate a model glider.
Pre-Class Assignment During class you will be designing and testing a wooden glider. In order to ensure a successful experiment, you must prepare your design and test logbook ahead of time. In addition to testing your own design, you will also be comparing your finished product to your competitors using the same criteria. Using excel, construct a logbook for your experiment using the reference material provided. Feel free to use additional resources with proper documentation. At a minimum your logbook should include: Group Member information Glider parameters (weight, dimensions, locations etc) Calculation for glide distance Other information may include room for sketches, notes about design decisions, and any other information you may want to have for later use.
Sample Logbook Wooden Glider Design and Testing Date:Dec 1,2009 Group Members:Erinecrede@vt.edu Willwiwalker@vt.edu Johnjanja710@vt.edu Instructions: Working in teams of 4, design and build a wooden glider using the materials provided. Be sure to document the design in your logbook including drawings, dimensions, weight etc. Glide Calculations: glide distance is the height multiplied by the lift to drag ratio drag is the dynamic pressure times the wing area and drag coefficient. L lift equal to the weight of the glider Parameters Toss Height (h): Weight: S V density Cd D L/D distance Final Glider Design: Weight: Tail span Tail Chord Wing Span Wing chord Fuse type Fuse Length
Material List/Cost for In Class Activity Material Unit Cost Total for WorkshopNotes Wood Sheet$0.25$93.75assuming 375 groups of 4 students Rod$0.10$37.50assuming 375 groups of 4 students Glue$2.80$70.00assuming 25 groups simultaneously working Single Use Material Total$3.15$201.25 Cutting Tool$2.80$70.00assuming 25 groups simultaneously working Scale$5.00$25.00one scale per classroom (5 simultaneous classes) Tape Measure$2.00$10.00one per classroom (5 simultaneous classes) Ruler$1.00$25.00assuming 25 groups simultaneously working Reusable Material Total$10.80$130.00 Workshop Total$13.95$331.25
In Class Activity Class Activity Outline (0-5 min) Pass out materials to each group (5-10 min) Explain overview of activity (10-35 min) Students build gliders and document in logbook (35-45 min) Glider Competition! (45-50 min) Students collect “competitor’s” information and final activity wrap Note: 10 minutes available for use at instructor’s discretion
In Class Activity General Activity Instructions: Working in teams of 4, design and build a wooden glider using the materials provided. Be sure to document the design in your logbook including drawings, dimensions, weight etc. Final Glider Design: Weight:0.15lbs Tail span4inches Tail Chord1inch Wing Span12inches Wing chord2.5inches Fuse type0.25 inch diameter Fuse Length12inches
In Class Activity Prior to the test flight, predict the glide time and distance your glider should be able to attain. Be sure to note these predictions in your logbook. Glide Calculations: glide distance is the height multiplied by the lift to drag ratio drag is the dynamic pressure times the wing area and drag coefficient. Lliftequal to the weight of the glider Parameters Toss Height (h):5ft Weight:0.15lbs S0.208ft2 V20ft/s density0.002241sl/ft3 Cd0.08 D0.007458lb L/D20.112 distance100.562ft
In Class Activity Glider Competition! Each team should provide the following information about your glider prior to testing: (instructor can compile a set of tables) Wingspan Chord Fuselage type (rod thickness) Weight Throwing Height Location of wing leading edge Location of tail leading edge Each team should make notes/sketches about each glider.
In Class Activity Briefly comment on the results of the test flight prior to leaving class. Be sure to copy the competitors dimensions into your logbook for future calculations. If a single logbook was used for the activity, be sure to share the results among the group members. Glider #Weight: Tail span Tail Chord Wing Span Wing chord Fuse type Fuse Length Toss VelocityL/D Glide Distance
Out of Class Assignment Complete Logbook! Each student should complete their logbook at home to submit the following week. In addition to the class activity, address the following: 1.Create a table or chart to compare each glider, comment on the designs. 2.Which glider should have gone the farthest based on the predicted glide distance? 3.Which glider actually travelled the farthest? Comment on the possible reasons for this discrepancy 4.If you were able to do this activity again, what would you have done differently: a.As part of the preparation? b.As part of the overall design?
Possible Test Questions 1.For a given set of aircraft parameters, calculate the glide distance. a. Five numeric answer choices 2.Which of the following are not directly used to calculate gliding distance? a.Aircraft weight b.Aircraft drag c.Height above ground d.Wing shape e.None of the above 3.Which of the following is generally true? a.Predicted glide distance is greater than actual glide distance b.Predicted glide distance is less than actual glide distance c.Predicted glide distance is equal to actual glide distance 4. Which of the following not a use for a logbook? a.Planning an experiment b.Storing data from an experiment c.Creating a record for experimental data collection d.None of the above e.All of the above
Summary The activity described addresses the following learning objectives: While this activity was modeled after a popular aerospace activity, experimental design is an important concept for most engineering disciplines, specifically related to planning ahead, reflection on design decisions and theoretical versus actual performance measures. Questions?? 1.Introduce students to experiment logbook preparation and use. 2.Introduce students to gliding flight, specifically performance calculations. 3.Construct, test, and evaluate a model glider.