ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

3pEA5. The impact of sampling location on the minimization of noise in a cavity with flexible walls.

Kenneth A. Cunefare

Van Biesel

George W. Woodruff School of Mech. Eng., Georgia Inst. of Technol., Atlanta, GA 30332-0405

Steven Engelstad

Lockheed Aeronaut. Systems Co., Marietta, GA 30063

Many transportation systems, e.g., aircraft and automobiles, have significant interior noise levels. There is substantial interest to reduce such interior noise levels, while minimizing weight penalties. Since the noise field inside such vehicles cannot, in general, be determined analytically, numerical techniques are commonly used to model the structural response of the cavity walls and the accompanying coupling to the interior space. These approaches may then be coupled to an optimization algorithm to determine how the walls should be designed so as to minimize the interior noise. However, a significant feature of such an approach is the need to sample the interior field at a number of points within the volume. This presentation will evaluate how the distribution of the sampling points within a volume may influence the efficiency of an optimization algorithm. The relative merits of sampling points distributed throughout the volume will be compared to points restricted to a layer near the cavity boundaries. The subject cavity will be a simple model of an aircraft fuselage.