Introduction to Experimental
Design and Testing
Engineering Education-EngE 1024
December 1, 2009
Created by: Erin Crede
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
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
Wooden Glider Design
and Testing
Date: Dec 1, 2009
Group
Members:
Erin
Will
John
ecrede@vt.edu
wiwalker@vt.edu
janja710@vt.edu
equal to the weight of the glider
Instructions:
Parameters
Toss Height (h):
Weight:
S
V
density
Cd
D
L/D
distance
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:
Tail span
Tail Chord
Wing Span
Wing chord
Fuse type
Fuse Length
Material List/Cost for In Class Activity
Material
Wood Sheet
Rod
Glue
Unit Total for
Cost Workshop
Notes
$0.25 $93.75 assuming 375 groups of 4 students
$0.10 $37.50 assuming 375 groups of 4 students
$2.80 $70.00 assuming 25 groups simultaneously working
Single Use Material Total $3.15
$201.25
Cutting Tool
Scale
Tape Measure
Ruler
$70.00
$25.00
$10.00
$25.00
$2.80
$5.00
$2.00
$1.00
Reusable Material Total $10.80
$130.00
Workshop Total
$331.25
$13.95
assuming 25 groups simultaneously working
one scale per classroom (5 simultaneous classes)
one per classroom (5 simultaneous classes)
assuming 25 groups simultaneously working
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:
Tail span
Tail Chord
Wing Span
Wing chord
0.15
4
1
12
2.5
Fuse type
Fuse Length
0.25
12
lbs
inches
inch
inches
inches
inch
diameter
inches
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.
L
lift
Parameters
Toss Height (h):
Weight:
S
V
density
Cd
equal to the weight of the glider
5ft
0.15lbs
0.208ft2
20ft/s
0.002241sl/ft3
0.08
D
L/D
distance
0.007458
lb
20.112
100.562
ft
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
Tail
Tail
#
Weight: span Chord
Wing
Span
Wing
chord
Fuse
type
Fuse
Length
Toss
Velocity
L/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.
2.
3.
4.
Create a table or chart to compare each glider, comment on the designs.
Which glider should have gone the farthest based on the predicted glide
distance?
Which glider actually travelled the farthest? Comment on the possible
reasons for this discrepancy
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:
1.
2.
3.
Introduce students to experiment logbook preparation and use.
Introduce students to gliding flight, specifically performance calculations.
Construct, test, and evaluate a model glider.
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??