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The exhaust manifold heat shield is made of different material layers and is bolted to the engine exhaust manifold. The exhaust manifold heat shield has been identified as a potential major noise contributor among the engine components during normal operation, which is to protect nearby components from damage due to high heat. To reduce the noise radiated from the exhaust system, a thermal acoustic protective shield (TAPS) has been developed to act as a partial acoustic enclosure. This paper will discuss the importance of controlling NVH and what can be done design-wise to improve the TAPS characteristics. The paper discusses the impact of damping and vibration, how they are modeled. Further the present study analyzes the radiated sound pressure level (SPL) of a thermal acoustic protective shield by using the finite element analysis (FEA). The analyses are performed using the fully coupled structural-acoustic method and the sequentially coupled structural-acoustic method.

Thermal Acoustic Protective Shields (TAPS) serves dual purpose. They provide a thermal barrier, which protects sensitive components from the exhaust manifold radiated energy. They also act as an acoustic insulator, which reduces the amount of sound power transmitted from the engine to the environment. The design of multi layered TAPS has, until recently, relied on trial and error or simplified numerical analyses. The following work describes efforts to develop a comprehensive numerical methodology for the initial forming of the components, which accounts for most of the physics of the problem. The simulation accounts for the complete forming operations of the part, i.e. edge folding, multi layer assembly, edge crimping, beading, and final forming. Non-linear effects are accounted for such as interlayer frictional dissipation, plastic anisotropy and self-contact.