Nonlinear Frequency Response Analysis of Distributed Parameter Systems with One Spatial Coordinate

The objective of this paper is to investigate possible strategies for applying nonlinear frequency response (NFR) analysis based on the concept of higher-order frequency response functions to distributed parameter systems. Three approaches are presented and compared: one based on applying the existing procedure directly to the partial differential model, and two based on approximation of the distributed parameter system with a series of lumped parameter segments. One of them treats the complete series of segments integrally, while the other treats it segment by segment, so it uses only the model of a single segment. A simple example, an isothermal plug-flow reactor with a simple reaction mechanism, is used as a case study. Pros and cons for all three approaches are given. The application of the nonlinear frequency response analysis based on the concept of higher-order frequency response functions to distributed parameter systems is evaluated systematically. In order to facilitate the understanding of the presented concepts, only single-input-single-output distributed parameter systems with one spatial coordinate are considered. image