Design and Analysis Consideration for Acoustical Baffles and Support Seats Under Seismic Loads and Exposed to High Temperature Operating Conditions

Abstract The objective of this paper is to provide the design and analysis method for acoustical elements (baffles) and their supports in a vertical cylindrical exhaust silencer system. Acoustic baffles are crucial components of a gas turbine exhaust system, as they are responsible for reducing noise levels to ensure compliance with jurisdictional limits. The overall performance of an exhaust system is dependent on both the gas flow dynamics of the exhaust duct and a functional and structurally reliable acoustic baffles. The structural requirements of the baffle and its support components are essential for avoiding structural failures under the combined effect of gravity / dead, seismic, and thermal loads. This paper presents an analytical numerical procedure for the analysis and design of new and existing acoustic baffles and their supports and guides. The analytical procedure discussed in this paper is justified by code provisions from ASCE 7-22 (Minimum Design Loads and Associated Criteria for Buildings and Other Structures), and ASME BPVC Section VIII Div 2 (ASME Boiler and Pressure Vessel Code). In high-temperature environments like the exhaust silencer, the ASME design limit theory is relevant for ensuring a safe design, as it defines allowable stress limits to prevent fatigue failure. A finite element analysis (FEA) for the case study acoustic baffles and their supports and guides using the outlined procedure provides controlling stress locations, estimate design life cycles, and assess maximum structural and thermal displacements. While the discussion in this paper focused on acoustic baffles and their supporting systems, the analytical procedure demonstrated could be adopted as a design or failure investigation analysis procedure for other components of the exhaust system in high-temperature environments, such as inlet transitions, base elbows, diffusers, etc.