Accession Number:

AD0654904

Title:

BAFFLE EFFECTS UPON ARRAY BEHAVIOR,

Descriptive Note:

Corporate Author:

NAVY UNDERWATER SOUND LAB NEW LONDON CONN

Personal Author(s):

Report Date:

1967-05-29

Pagination or Media Count:

33.0

Abstract:

Extensive computer calculations have been made on a 50-element planar array, which has 20 driven pistons and 30 undriven pistons of different mechanical impedance to simulate rigid and nonrigid baffles. Many different combinations of the driven transducer internal impedance and undriven baffle internal impedance have been used. The worse baffle condition appears to be when the mechanical reactance of the baffle is near the self-radiation reactance of the baffle pistons, which might be referred to as a resonant baffle condition. For fixed driving forces on the driven transducers and variable baffle mechanical reactance there was a large variation of acoustic power as the ratio of baffle mechanical reactance to self-radiation reactance passed through the values of 1 to -3. Another interesting phenomenon was seen when the internal impedance of the driven pistons was made large, so that all the driven pistons had the same velocity velocity control. When the baffle pistons were chosen perfectly rigid, no negative radiation resistances elements absorbing power were found, as would be expected. However, when the baffle pistons were chosen nonrigid, for some combinations of baffle mechanical reactance and steering angle, some of the driven pistons did absorb power from the rest of the array, even though they still had velocity control. It was also found that in some of the cases studied, the velocities of some of the baffle pistons exceeded the largest velocity observed for the driven pistons. Author

Subject Categories:

  • Acoustic Detection and Detectors
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE