CHAPTER 10 - EVALUATING THE COUPLING LOSS FACTOR

Abstract

This chapter focuses on the theoretical, numerical, and experimental methods for evaluating the coupling loss factor (CLF) among a variety of statistical energy analysis (SEA) subsystem types. The CLF is a parameter unique to SEA and is associated with a central result of SEA—that the average power flow between coupled mode groups is proportional to the difference in the average modal energies of the mode groups, with the proportionality factor, which includes the CLF, being independent of the energy levels. The CLF is defined in a manner similar to the definition of the damping loss factor η. The CLF is a measure of the rate of energy flowing out of a subsystem through a coupling to another subsystem, whereas the damping loss factor is a measure of the rate of energy flowing out of a subsystem through a dissipation mechanism. Sometimes there is not a clear distinction between the coupling and the damping loss mechanisms. Although the basic formulation of SEA is in terms of coupled modes, the direct evaluation of the CLF from this approach is often difficult because of the need to evaluate complicated integrals to average over space and frequency.