Study on the Impact of Variable Geometry Turbines on the Overall Performance of Aeroengines and Their Control Principles

Variable geometry turbine technology optimizes engine performance by regulating flow capacity, thereby enhancing both economy and stability. Although most research has concentrated on gas turbines, there is a lack of studies focusing on aeroengines. Further investigation is essential to understand the effects of variable geometry turbines on engine performance and to develop effective control strategies. This paper employs numerical simulations to calculate the characteristics of a variable geometry low-pressure turbine and integrates these results with a zero-dimensional turbofan engine model. The study examines how overall engine performance varies with different guide vane adjustment angles. The research results indicate that there is an optimal point for engine economy as the adjustable guide vane angle changes under high-pressure shaft speed control. A design methodology for regulating the adjustable turbine guide vanes is proposed to enhance engine economy. Additionally, by introducing a guide vane adjustment protection angle (Δαm), the control law for steady-state conditions is optimized for dynamic conditions. The method has been validated to enhance the economy of the engine while ensuring safe operation. The aforementioned research serves as a reference for the regulation and control of adjustable guide vanes in actual variable geometry turbines.