Viscous Damping of a Microperforated Plate in the Slip Flow Regime

Application ID: 113521

This tutorial model is of a micro perforated plate (also known as MPP) backed by a vibrating structure. This is a typical configuration in, for example, a MEMS microphone. The vibrating structure is not modeled explicitly, but just assigned a vibration velocity. The vibrating structure creates a pressure field that squeezes air through the perforated membrane. In the system there are two main sources for viscous losses: viscous losses in the squeezing flow between the gap between the vibrating structure and perforated membrane, and the viscous losses from the flow through the holes in the perforates. In this model the optimal hole size, to achieve minimal resistive losses, is analyzed for a given gap height and a fixed porosity (area ratio) for the perforates. The results are compared to the analytical results by Homentcovschi and Miles.

This model example illustrates applications of this type that would nominally be built using the following products: