Simulation of airborne paths using frequency based sub structuring

Frequency based sub structuring is routinely used to model structural dynamics. It provides a framework for connecting structural subsystems together, assessing path contributions, determining the effect of isolator modification, and inverse force identification. In this work, the methods are extended to acoustic subsystems including rooms and partial enclosures. Acoustic subsystems are characterized by their transfer functions, and the connections or energy paths between subsystems are modeled using transfer matrix approaches commonly used for analyzing muffler and silencer performance. The suggested approach is validated using boundary element simulation for two cases. In the first case, frequency based sub structuring is used to model two rooms (one room consisting of a source) connected by two ducts, and the response is predicted in the receiving room. In the second example, a single room with an acoustic source is connected to the exterior via two ducts, and the procedure is used to determine the insertion loss.