Experiments
A. Borgoltz and W. J. Devenport
Last Modified 21 January 2020
 
Background
The purpose of the experiments in AOE 3054 is to give you hands 
on experience in organizing, conducting, and documenting experimental tests. 
You will get to see in real life some of the phenomena you only saw in theory in 
previous classes. You will get hands on experience of experimental techniques 
and equipment typical of aerospace and ocean engineering applications (as well 
as learning about other techniques in the classes and online lectures). Above 
all, you will be encouraged to think independently about the experiments you are 
given and the equipment you are using, considering both their capabilities and flaws. 
None of the experiments have required procedures or pre-set measurement 
objectives (except for experiment 5, and there are good reasons here). It is up 
to you to decide on what they will be. In addition, none of the experiments have 
'expected results'. You are expected to open mindedly and objectively assess 
your own results, their limitations, and what they mean. Your results are unique 
and always have value as new and independent observations.
You 
are expected to keep comprehensive documentation of each experiment you perform 
in the form of a logbook. A logbook is like a detailed diary of your team's 
preparation for, and activity during, an experiment. All logbooks are kept in MS 
Excel. Logbooks are described in detail in
appendix 1. You will  be 
asked to write full reports on three selected experiments. Reports are also 
described in appendix 1, and 
report writing will be covered in class. You will have a chance to revise each 
report after you receive comments back from your instructor.
 
Lab 
Organization and Preparation
Experiments are held once every two weeks (except for experiment 6 which is 
done as part of instrumentation lab) and are performed in teams of 2 or 3 
students. All experiments assume that you have mastered the material in the 'Basic 
Concepts in Experiments' chapter of the lab manual and the
online lectures on "Statistical Data Analysis" 
and "Estimating Experimental Error". 
In particular you are expected to be comfortable with the concepts of 
uncertainty analysis, and be ready to make formal uncertainty estimates (a.k.a. 
error estimates) for all the measurements you make, and results you infer from 
them. All experiments assume you are familiar with MS Excel and how to generate 
a logbook.
When you have an experiment scheduled, your homework on that week 
will be to prepare for it. To prepare you should:
(a) View the relevant online 
lecture.
Background material for experiments 1, 2, and 3 is covered in the three 
online classes "Flow Visualization (Ex 1)", "Measuring Static Displacement and 
Deformation in Structures (Ex 2)", and "Measuring Velocity and Pressure in Fluid 
Flows (Ex 3)". These classes provide 
a broad overview of the technology in each of these areas, some of which you 
then get to use in each experiment.
(b) Carefully read the relevant chapter of 
the manual.  
It is important to be familiar with the descriptions of the measurement
techniques and experimental set up, as well as any theoretical or descriptive 
background. Experiment chapters also include a photographic equipment inventory. 
(c) Meet with the other members of your 
team and prepare a preliminary logbook. Your team members  will be listed on 
your individual schedule handed out during the introductory lab period. Together, 
you will need to decide on goals (try to 
develop at least one goal  not in the manual), on what measurements will be made, 
how tasks will be assigned and what  uncertainties will need to be 
estimated. This information should be recorded on the preparation page of a new 
logbook, generated using the logbook template (note that the template also 
includes many suggestions for preparation). Your team's homework grade is 
assessed on the contents of this preparation page. You must email your 
instructor a copy of this logbook before coming to lab. Note that 
you may be able to visit the lab before your test to check on equipment, if  you would find that helpful. Open 
times for Goodwin 140 will be posted on the course 
home page. 
 
 Exit Checklist
At the end of the experiment the team will need to complete the logbook and 
submit it to the instructor. The last few minutes of lab 
are a good time to identify the team you will be working with on your next 
experiment, and maybe look over the apparatus you will be using. 
For those experiments on which you will be writing reports (the first, third 
and fifth experiments you do) the end of the lab period is a good time to check that everybody has everything they need. The following suggestions
may be helpful. 
- 
Look over the 'Recommended Report Format' section of the manual chapter. Do you have a good sense of
what the objectives in your report will be, how you will describe what
the various results mean, what the report conclusions are likely to be?  There is 
no requirement
that everybody in the team have the same objectives/conclusions, but it
is critical that the team discuss this before leaving the lab, so that
everyone is as well informed as possible. It is good to exchange ideas
as a team about how you are going to write the report - this will save
you a lot of time later.
- 
Has the team discussed how the data could/should be further (a) analyzed and (b)
plotted, so as to make the most sense? Should the velocities/pressures/distances/strains
be normalized? Plotted against what? On the vertical or horizontal axis?
With error bars? What errors? If you are not sure about some data (why
it was taken, how it should be plotted) it is your responsibility to initiate
a team discussion (and logbook entry?) on this issue before everybody
leaves the lab.
- 
Have you got all the information in the logbook you are going to need to
describe all the apparatus, instrumentation, methods, coordinate systems,
materials, etc.? Does anyone in the team have ideas for items for which
model no. info, dimensions, photos are missing and need to be added to
the logbook? Are there any obvious items not in the logbook (e.g. this
measurement/tunnel/probe was lousy/great - just remember to include specifically
why)? Have someone in the team skim the manual chapter for missed items/ideas.
- 
Has the team discussed how good/bad/useful the various pieces of data
you have are? You will be expected to provide error/uncertainty estimates
along with all the results presented in your report. Have you discussed
in the team how large these errors might be? 
Are they calculated (or is the information needed to calculate them) in
the logbook? Can anybody think of any further error sources/confounding
factors? Is there consensus over what data is most reliable? Least reliable?
Those factors in the experiment that most limit the applicability/validity
of your conclusions?
 
 Instructions for the 
Introductory Lab
To introduce 
you to the experiments part of this course, an introductory lab will be held at 
the start of the semester. Prepare for this lab period by reading the Introduction 
section of the course manual, this (overview) section and appendix 1 describing 
logbooks and lab reports. Look particularly at the logbooks. Download and check 
out the logbook template and sample logbook. You will need to bring to lab:
1.
  Your laptop
2. A digital copy of the
logbook template can be found in Appendix 1.
 
Your lab will 
be held in Goodwin 140 which is in the ground floor of Goodwin Hall where the open 
jet wind tunnel is sited. The best way to get there from Randolph Hall is to take the stairs between Whittemore and Durham Hall, walk across the Perry Street Parking Lot and enter Goodwin Hall from the main entrance. Once you enter the main hall where the Rolls Royce aircraft engine is suspended, Goodwin 140 is the first lab on your left.  
The meeting 
will include the following.
  - First you will meet your teaching 
  assistant for the lab experiments. (You will meet your Instrumentation Lab 
  instructor at the first Instrumentation Lab meeting). Your TA coordinates the lab 
  experiment periods and will grade your experiment logbooks and lab reports. 
  They serve as a primary point of contact for you. Make sure you record their 
  information.  
- You will get an individualized schedule (on paper) that 
  will show when you are doing each experiment and instrumentation lab period 
  and with whom. Make sure you understand the sheet. You will find that for each 
  lab you are working in a team of 2 or 3 students. Team assignments are 
  different most weeks.
- You, and all the other student members of the group, 
  will introduce yourselves so you can recognize those people you will be 
  working with on each experiment. Everyone should confirm that their contact 
  information (email) on the individual schedules is correct. This contact info 
  is critical since it will allow students performing the same experiment at the 
  same time to communicate in advance to prepare for that experiment.
- Your TA will explain how the group labs work, how it is 
  the students responsibility to plan and perform the experiment, how 
  experiments are expected to run for the complete lab period. Make sure you 
  understand. Now is the time to ask questions if there is anything you don't understand.
  They will explain what preparation is expected for a lab (a preparation logbook) and how it is 
  submitted (through CANVAS prior to the lab). They will also explain what a 
  logbook is, how and when it is submitted (also through CANVAS at the end of lab), how it is graded and how comments are returned to you. 
  Logbooks, including preparation, earn team grades i.e. all the members of a 
  team in attendance for the same experiment get the same grade.
- You will learn about computer use in the lab. Students 
  are expected to use their own laptop computers in lab. This is the time to let your TA know if you foresee any difficulties. You will need your laptop 
  to write your logbook, download photos from the digital cameras (you are 
  welcome to use your own digital cameras or camera phones as well) and, in 
  Instrumentation Lab, take computerized measurements.
- You will get to see how to use the equipment in the lab 
  that is used for experiments 1-4. This is your chance to get a really good 
  look at things without the pressure of an experiment to complete. You are 
  expected to cast an objective and critical eye on the equipment. You will have 
  to objectively judge (or guesstimate) its accuracy when you do these 
  experiments.   
- Once you have been introduced to all the equipment you 
  should meet with the team members you will be working with during next week's 
  experiment (check your schedule to see who they are and go meet them next to 
  that setup). Along with them you should: 
    
    - Try out all the hardware for the experiment
- Try out your laptop in the lab. Can you get a wireless 
    connection in the lab? If not let your TA know.
- Open the logbook template in your computer and 
    start a logbook preparation.
- Try out the digital camera.
- Practice getting pictures from the camera into your 
    logbook. To avoid huge files use the camera on its lowest resolution. Also, 
    save the photos from the camera on your computer and then use 
    Insert>Picture in Excel, rather than importing them directly. Learn to use the 'Compress Pictures' feature in Excel - on the Picture toolbar (it works in Word too).
- Try using the USB jump drive to transfer the 
    logbook to the computers of other team members if needed .
 
  
    - Try out for yourself all the equipment in your 
    experiment.
- Start your preparation for the experiment as suggested 
    in the relevant section of the course manual.
- Be sure to return all equipment and furniture to the state it was in when 
  you arrived (as you will need to do at the end of every lab period). In particular, make sure you return memory cards to the digital cameras.