A Real-Time Transient Model of CF6 Turbofan Engine

In traditional aeroengine modeling, the nonlinear equations of engine model are generally solved through iterative algorithm. However, due to the strong nonlinear characteristics of the equations, the iterative model often fails to converge at some points of the full envelope and has a poor real time performance. In order to solve the problems, this paper proposes a non-iterative modeling method based on volume effect. In this method, several variables and differential equations of volume dynamics in aeroengine are introduced to the nonlinear equations, as a result, the whole set of equations becomes closed-form and can be solved without iteration. The non-iterative model of a gas turbine engine is written in matlab code. Furthermore, an open-loop simulation is carried out in matlab/simulink, both under groud and altitude condition. Meanwhile, the non-iterative model is verified by GSP11. The results illustrate that the non-iterative model provides good performance both in the stability and accuracy of solutions.