Kimball Green Kimball Green
Office: 310 New Engineering Building Mechanical Engineering Department Tel: 540-231-2910 Virginia Tech Fax: 540-231-2903 Blacksburg, VA 24061-0261 E-mail: kimball@vt.edu
Born in Martinsville, Virginia. Received B.S. in Mechanical Engineering in May 1999 from Virginia Tech with Cum Laude honors. Currently working towards a Master's degree in M. E., expected graduation date of August 2000. A member of Alpha Phi Alpha Fraternity, ASME, Pi Tau Sigma, Tau Beta Pi, SAE, and Golden Key National Honor Society.
Motivation: Active Noise Control in Launch Vehicle Payload Fairings. A very high noise level inside the fairing, or housing, is a problem that affects the payload, therefore actions have been taken to create an active noise control solution. However due to the high dollar amount associated with sending a payload into space, approximately $10,000 dollar a pound, the solution needs to be as light as possible. Conventional speaker methods commonly used in active noise control make for an expensive endeavor. Therefore, through the use of lightweight smart materials, we hope to create a noise control solution that will be economical as well as useful.
Created a piezoceramic transducer, or speaker, that will be inserted into a simplified model of the fairing. Coupling the resonances of the piezoceramic speaker to the acoustic modes of the tube, should provide damping of the acoustic modes and thus a noise level reduction inside the tube. Below are pictures of the piezoceramic speaker without the housing and test setup.
a) b)
Figure 1: a) Un-optimized piezoceramic speaker with aluminum flexures. b) Six foot lexan tube with conventional speaker for external acoustic source
a) b)
Figure 2: a) front view of optimized piezoceramic speaker, b) back view of optimized piezoceramic speaker
Leo, D.J., Green, K., Mauck, S., "Sound absorbing transducers for interior noise control," accepted for publication in the Active 99 Conference, Ft. Lauderdale, FL.
Air Force Office of Scientific Research