Development of Bond Graph Approches for Modeling of a Non-isentropic Nozzle

In the papers published on compressible fluid using Pseudo Bond Graph approach، isentropic flow is assumed. However in a converging- diverging nozzle، for a specific pressure ratio، the assumption of isentropic flow is invalid. For the purpose of considering normal shock effects، this paper introduces a new field (NIKE-field) to the pseudo bond graph. The output of the new field can be also used to determine normal shock position and to extract momentum equation as well. In the following، the methodology developed in this paper has been applied a simple pedagogic example. Simulation result is validated by comparison with the analytical result. As the new field can be modeled non-isentropic flow، it can be used to for modeling rockets motors and thrusters in transient state. One of another advantage of new field (NIKE-field) is that it can be easily used in many software applications like MS1، SYMBOLS2000 and 20SIM®; therefore، With regard to the systematic derivation of a mathematical model from a bond graph in these softwares، there is no need to derive any state equations and their solutions.