Development and Validation of a Physics-Based, Dynamic Model of a Gas Turbine

Abstract

This paper presents and validates a physics-based, dynamic model of a gas turbine. The model is an extension of that proposed by Badmus et al. [1], such that representation of a complete gas turbine is achieved. It includes new models of several gas turbine components, in particular the turbine and compressor, and also applies a well known method for prescribing boundary conditions [10] to the gas path. This model first uses data from a previously published, static model of the same gas turbine to determine this dynamic model’s many so-called ‘forcing terms’. A least-squares optimisation is then undertaken to estimate the shaft inertia and the thermal inertia of system components using transient test data. Importantly, these optimised results are all close to physically reasonable estimates. Further, they show that the shaft dynamics are only significant for a short period at the start of most transients, after which the dynamic effects of thermal storage are dominant. The complete gas turbine model is then validated against transient test data. Whilst the simulated traces demonstrate some steady-state error arising from the static model [12], the overall system dynamics appear to be captured well. Since steady-state error can be integrated out in a control system, this suggests that the proposed dynamic model is appropriate for use in a model-based, gas turbine controller.

The Nonlinear Single Controller of DGEN380 Aero Engine Design

“…Equation (8) sets relation between rotary parts and shaft speed. Least squares method is the identification tool of this study that is invoked in MATLAB tool box [5,6]. And the test data of rotary parts is obtained by test bench of DGEN380.…”

“…The purpose of this research is then to propose that a nonlinear control approach for DGEN380 aero engine is to implement the power management of the aero engine. The main achievements are the nonlinear model of DGEN380 aero engine and the advanced nonlinear controller which both can be used for steady control and transient control [4][5][6][7][8][9].…”