Abstract: The concept of signal flow graph was introduced into the mechanism modeling process to describe the fluid network. Various structures in the fluid network were classified as node and branch, and establish the algorithm relationship between node pressure and bransh resistance. Aiming at the characteristics of nonlinear and strong coupling of fluid network, the node pressure was expressed by Taylor series near the quiescent operation point using the linear model to describe the nonlinear network. A method was proposed which used the directed graph to improve the computational efficiency of the admittance matrix at the working point. Based on the analysis of the new network models, the general structure of segmented model of fluid network was given. Through an example, the method and process of establishing the fluid network model were elaborated by using the above method. The modeling process indicates that this method is simple and effective, and the segmented model obtained has a strong practical value.

Key words: fluid network, mechanism model, signal flow graph, sparse matrices