FIELD THEORETICAL MODEL OF ACOUSTIC PROPAGATION WITH ROUGH BOUNDARIES

Award Information
Agency: Department of Defense
Branch: Navy
Contract: N/A
Agency Tracking Number: 6184
Amount: $49,608.00
Phase: Phase I
Program: SBIR
Awards Year: 1987
Solitcitation Year: N/A
Solitcitation Topic Code: N/A
Solitcitation Number: N/A
Small Business Information
Nichols Research Corp
4040 S Memorial Pkwy, Huntsville, AL, 35802
Duns: N/A
Hubzone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: N
Principal Investigator
 DR L I PERLOVSKY
 (617) 246-4200
Business Contact
Phone: () -
Research Institution
N/A
Abstract
A NOVEL APPROACH IS TAKEN IN THIS PROPOSAL FOR THE RIGOROUS TREATMENT OF THE PROBLEM OF ACOUSTIC WAVE PROPAGATION THROUGH SHALLOW WATER BOUNDED BY ICE AND BOTTOM WITH ROUGH SURFACES. THIS TREATMENT INCLUDES A FIELD-THEORETIC CONSIDERATION OF WAVE PROPAGATION AND A STATISTICAL-PHYSICS MODEL OF ROUGH ICE AND BOTTOM SURFACES. THE FIELD-THEORETIC MODEL SHALL ACCOUNT FOR ALL MODES OF WAVE PROPAGATION IN LAYERED MEDIA AND TREAT THE INTERACTION WITH ROUGH SURFACES BY EXPANDING THE EXACT SOLUTION INTO PERTURBATION SERIES IN POWERS OF A SMALL PARAMETER, THE RELATIVE ENERGY LOSS PER WAVELENGTH. IT ACCOUNTSFOR WAVE INTERACTIONS WITH FLUCTUATIONS OF BOTH GEOMETRICAL SHAPE AND RIGIDITY, WHICH ARE KNOWN TO CAUSE SIGNIFICANT ENERGY LOSSES. A MODEL BASED ON THE THEORY OF PHASE TRANISTIONS BETWEEN LIQUID, NONRIGID, AND RIGID PHASES IS USED TO DESCRIBE THE ROUGH ICE AND BOTTOM SURFACES. THIS MODEL WILL PREDICT THE RIGIDITY FLUCTUATIONS IN ICE ON THE BOTTOM AND ALSO RELATE THE GEOMETRICAL DISTRIBUTION OF ICE AND BOTTOM ROUGHNESS TO THE AVERAGE LOCAL ENERGY DISTRIBUTIONS ON DIFFERENT SCALES. THE MODEL RESULTS ARE COMPARED WITH EXISTING DATA.

* information listed above is at the time of submission.

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