A Novel Dynamic Surge Modeling Framework for Gas Turbines: Integration of Compressor Variable Geometry

Gas turbines are complex mechatronic systems that require reliable dynamic models to support automated operation under varying aerodynamic conditions. This study presents a novel dynamic surge modeling framework that integrates compressor variable geometry into a gas turbine component-level model. A physics-based formulation is developed in which the influence of inlet guide vane (IGV) deflection is incorporated through sensitivity-based parameterization and a physics-informed extension of compressor performance characteristics. The proposed framework captures the nonlinear interaction between compressor surge dynamics and component-level system behavior, enabling consistent prediction of instability onset and dynamic stability margins over a wide range of operating conditions. Model verification through stability analysis, phase-space characterization, and time-domain simulations demonstrates that the framework reproduces key features of classical compressor surge and quantifies the impact of variable geometry on system stability. The results show that the proposed model provides a practical and computationally efficient basis for control-oriented surge analysis, including stability monitoring and surge delay assessment. By coupling the IGV-aware surge dynamics with a gas turbine component-level model, the proposed method enables control-oriented, automation-ready simulation for gas turbine design and control.