3rd Annual Meeks Memorial Acoustics Workshop, 2009

 

Rose-Hulman Institute of Technology


 Monday July 6, 2009 through Thursday July 9, 2009

This workshop is dedicated to the memory of Wilkison W. Meeks, Professor of Physics at Rose Polytechnic Institute and Rose-Hulman Institute of Technology. Dr. Meeks was a teacher of acoustics, an acoustics researcher, and the author of an acoustics textbook.  The workshop will be conducted by Michael J. Moloney, longtime colleague and friend of Dr. Meeks. Partial support for this workshop comes from funds provided by Dr. Meeks' widow and daughters for the encouragement of study and achievement in acoustics.

 

The main emphasis is on acoustics experiments which are fairly simple to carry out, and fairly easy to interpret.
Each experiment will be demonstrated, and some theoretical support will be given for each.


The workshop requires that participants bring their own laptop computers.


Data acquisition. Rose-Hulman has Vernier LabPro interfaces for acquiring data (see below). This is the standard method of operating at Rose, but we will also present freeware programs which one might use to acquire and analyze data. There is a free oscilloscope program which operates through a microphone signal entering the sounc card input, giving a simulated scope signal. Another free program for sound analysis is Audacity,  with very reasonable properties. Both of these will be demonstrated, and instructions given to those interested.


Data will usually be taken with the aid of Vernier LabPro interfaces available at Rose-Hulman, interfaced to Vernier Logger Pro software. (Vernier Software has kindly agreed to permit the use of Logger Pro software for the duration of the workshop, if a participant does not own it. Such Logger Pro software must be removed at the end of the workshop.)

 

Participants are not obligated to carry out all experiments. Four days have been allocated, which should allow for thorough exploration of all experiments. (Three days may be sufficient for some participants, depending on their interests.)

 

The following experiments will be set up and available throughout the workshop:

 

Measure the Q values of a set of pvc pipes of varying diameter but all having the same resonant frequency. Narrow tubes have a low Q due to viscous losses at the wall, radiating little from their ends. As tube diameter increases, Q increases to a maximum and decreases. This is due to competition between wall losses and radiated sound out the ends.

 

The resonant frequencies of freely-suspended rods will be measured, both for lateral and longitudinal vibrations.  Participants are encouraged to use  inexpensive electrical conduit to build a set of wind chimes if they desire.

 

            There are a number of simple and interesting ultrasonic experiments:

 

Helmholtz resonators will be studied by changing the volume or the neck length. Data can be fitted and checked against the theory.


Wind chimes (participants may opt to make a set)


Cyindrical resonators

 

            The resonant frequencies of resonators can be measured for

  pipes with one or more side branches

Helmholtz resonators in their higher modes

(Relatively accurate modeling of all these can be done using RK2 numerical integration in a spreadsheet or program, following the ideas of Ian D. Johnston)


For those interested in waves travelling in a dispersive medium. a 30-ft length of suspended music wire or slinky can be set up. When the wire is struck in the middle, high-frequency waves arrive before lower frequency ones. These waves can be seen to be travelling at the group velocity and not the phase velocity. The Euler-Bernoulli theory makes a simple prediction, which is nicely verified using the experimental arrival times of different frequencies. This can be done as a live demonstration. A Maple simulation will be available to participants as well.

 

The approximate schedule is as follows:

 

Sunday  - arrive at Rose-Hulman between 4 PM and 8 PM, unless staying off campus.

 

Monday Morning  (9AM)

            Demonstration and discussion of Q values of pvc pipes.

            Demonstration and discussion of the set of short ultrasonic experiments

 

Monday Afternoon  (1 PM)

            Demonstration and discussion of lateral vibrations of freely suspended bars

             Demonstration and discussion of dispersive waves travelling along a music wire or slinky

Tuesday Morning,  (9AM)

            Demonstration and discussion of Helmholtz resonators

            Demonstration and discussion of pipes with a sharp change in area

 

Tuesday Afternoon, (1 PM)

            Demonstration and discussion of Ian Johnston's 1-D model of resonators

                        (this handles holes in resonators, side branches, changes of area, etc.)

Demonstration/discussion of RK2 integration used in Excel for Johnston's model

            Demonstration and discussion of using scroll bars (sliders) in Excel to do 'animations'

 

Wednesday  and Thursday

            Demonstrate resonances in cylindrical resonators (empty 50-CD containers)
            Repeat any of the earlier demonstrations/discussions as needed

(Any participant who brings a woodwind instrument is free to numerically model it and compare to the actual notes of the instrument.)

 -------------------------------------------------------------------------------------------------------------------------------------


____ I cannot attend a  2009 workshop but would be interested in one offered in the future.

 

There is a workshop registration fee of $125.

This is payable to Rose-Hulman Institute of Technology (check or credit card)

three weeks prior to the workshop.

Room (single or double occupancy in Rose-Hulman dorms) and board will be provided.

(Some limited funds are available to help defray travel and other costs.)

 

If the workshop is oversubscribed, strong consideration will be given to earlier applications with paid registration.

 

 

3rd Annual Meeks Memorial Workshop Application form  2009

 

Email to :    moloney@rose-hulman.edu

 

Or mail to    Dr. Michael Moloney

                    Rose-Hulman Institute of Technology

                    5500 Wabash Avenue, CM 180

                    Terre Haute, IN 47803

 

Participant's Name _______________________________________________________

 

Home Address ___________________________________________________________

 

Institution ______________________________________________________________

 

Email address (important)_____________________________ 

 

Telephone number _______________________

 

____  My laptop is a Mac and I will need a Mac version Logger Pro software for this workshop.

 

Please explain how you expect to benefit, and how your students will benefit from your taking this workshop.

 

 

 

 

 

 

           


 

Payment is by

 

_______ Personal check

 

______  Credit card                            

Type of card   _____Visa        ____ Mastercard   ____   Other ________

                                   

Name as it appears on the card

 

                                    Card Number

 

                                    Expiration date

 

 

For additional information or questions,

 

Email moloney@rose-hulman.edu        

 

Phone (moloney) 812 877 8302,  (PHOE office) 812 877 8309

 

FAX (Physics & Optical Eng ) 812 877 8023

 

 

Additional comments: