Department News
New Approximations of External Acoustic-Structure Interaction Models
Seminar Date
2004-10-18
Author
지국현
Date
2004-10-18
Views
1966
1. 제 목 : New Approximations of External Acoustic-Structure Interaction Models
2. 연 사 : Professor K.C. Park (University of Colorado at Boulder )
3. 일 시 : 2004년 10월 20일 (수) 11:00 - 13:00
4. 장 소 : 서울대 신공학관(301동) 117호 세미나실
5. 내 용 : A key modeling challenge in acoustic scattering has been that the governing integral equations, whether one employs the Kirchhoff or Helmholtz formula, are difficult to evaluate other than for analytical shapes such as a sphere, paraboloid, or infinite cylinder. This motivated a number of investigators in the past to propose varying approximations so that general scattering surfaces can be efficiently modeled. We first review the origin of the retarded potential for monochromatic wave propagation, which yields the Laplace-transformed integral equations for spherical waves. We then employ a series of consistent, hierarchical approximations to derive a first-order form, and a second order form of the governing acoustic field models whose coefficient matrices are obtained via the standard boundary integral method. The newly derived approximate equations are then compared to existing approximate formulations, including the widely used doubly asymptotic approximate models. Comparison of the present approximations with existing approximate models indicates that the present approximate models are shown to correct the overly conservative plane wave approximations for capturing the high-frequency responses adopted in most existing approximations. Thus, the present approximations appear to offer potential for improving the accuracy, especially for intermediate frequency ranges, which has been the weakest feature of many existing models. Finally, coupling the present approximate acoustic models with structural medium-frequency vibrations are discussed.
6. 약 력 :
1970 Stanford University, M.S.
1974 Clarkson College, Ph.D.
1973-1985 Senior Staff Scientist at Lockheed's Palo Alto Research Laboratory.
1985-present Professor, Department of the Aerospace Engineering Science,
University of Colorado at Boulder.
7. 문 의 : 기계항공공학부 김승조 교수 (☏ 880-7388)
2. 연 사 : Professor K.C. Park (University of Colorado at Boulder )
3. 일 시 : 2004년 10월 20일 (수) 11:00 - 13:00
4. 장 소 : 서울대 신공학관(301동) 117호 세미나실
5. 내 용 : A key modeling challenge in acoustic scattering has been that the governing integral equations, whether one employs the Kirchhoff or Helmholtz formula, are difficult to evaluate other than for analytical shapes such as a sphere, paraboloid, or infinite cylinder. This motivated a number of investigators in the past to propose varying approximations so that general scattering surfaces can be efficiently modeled. We first review the origin of the retarded potential for monochromatic wave propagation, which yields the Laplace-transformed integral equations for spherical waves. We then employ a series of consistent, hierarchical approximations to derive a first-order form, and a second order form of the governing acoustic field models whose coefficient matrices are obtained via the standard boundary integral method. The newly derived approximate equations are then compared to existing approximate formulations, including the widely used doubly asymptotic approximate models. Comparison of the present approximations with existing approximate models indicates that the present approximate models are shown to correct the overly conservative plane wave approximations for capturing the high-frequency responses adopted in most existing approximations. Thus, the present approximations appear to offer potential for improving the accuracy, especially for intermediate frequency ranges, which has been the weakest feature of many existing models. Finally, coupling the present approximate acoustic models with structural medium-frequency vibrations are discussed.
6. 약 력 :
1970 Stanford University, M.S.
1974 Clarkson College, Ph.D.
1973-1985 Senior Staff Scientist at Lockheed's Palo Alto Research Laboratory.
1985-present Professor, Department of the Aerospace Engineering Science,
University of Colorado at Boulder.
7. 문 의 : 기계항공공학부 김승조 교수 (☏ 880-7388)
