In an extraction turbine, pressure of the extracted steam and rotate speed of the rotor are two important controlled quantities. The traditional linear state feedback control method is not perfect enough to control th...In an extraction turbine, pressure of the extracted steam and rotate speed of the rotor are two important controlled quantities. The traditional linear state feedback control method is not perfect enough to control the two quantities accurately because of existence of nonlinearity and coupling. A generalized minimum variance control method is studied for an extraction turbine. Firstly, a nonlinear mathematical model of the control system about the two quantities is transformed into a linear system with two white noises. Secondly, a generalized minimum variance control law is applied to the system. A comparative simulation is done. The simulation results indicate that precision and dynamic quality of the regulating system under the new control law are both better than those under the state feedback control law.展开更多
Thermal boundary conditions of the turbine disk cavity system are of great importance in the design of secondary air systems in aero-engines.This study aims to investigate the complex heat transfer mechanisms of a rot...Thermal boundary conditions of the turbine disk cavity system are of great importance in the design of secondary air systems in aero-engines.This study aims to investigate the complex heat transfer mechanisms of a rotating turbine disk under high-speed conditions.A high-speed rotating free-disk model with Dorfman empirical solutions is developed to evaluate the heat transfer performance considering various factors.Specifically,the influence of compressibility,variable properties,and heat dissipation is determined using theoretical and numerical analyses.In particular,a novel combined solution method is proposed to simplify the complex heat transfer problem.The results indicate that the heat transfer performance of a free disk is primarily influenced by the rotating Mach number,rotating Reynolds number,Rossby number,and wall temperature ratio.The heat transfer temperature and Nusselt number of the free disk are strongly correlated with the rotating Mach number and rotating Reynolds number.Analysis reveals that heat dissipation is a critical factor affecting the accurate evaluation of the heat transfer performance of the turbine disk.Thus,the combined solution method can serve as a reference for future investigations of flow and heat transfer in high-speed rotating turbine disk cavity systems in aero-engines.展开更多
文摘In an extraction turbine, pressure of the extracted steam and rotate speed of the rotor are two important controlled quantities. The traditional linear state feedback control method is not perfect enough to control the two quantities accurately because of existence of nonlinearity and coupling. A generalized minimum variance control method is studied for an extraction turbine. Firstly, a nonlinear mathematical model of the control system about the two quantities is transformed into a linear system with two white noises. Secondly, a generalized minimum variance control law is applied to the system. A comparative simulation is done. The simulation results indicate that precision and dynamic quality of the regulating system under the new control law are both better than those under the state feedback control law.
基金supported by the National Science and Technology Major Project of China(2017-II-0011-0037)In addition,special thanks are addressed to the support of China Postdoctoral Science Foundation(2023M742834)Guangdong Basic and Applied Basic Research Foundation,China(2023A1515011597).
文摘Thermal boundary conditions of the turbine disk cavity system are of great importance in the design of secondary air systems in aero-engines.This study aims to investigate the complex heat transfer mechanisms of a rotating turbine disk under high-speed conditions.A high-speed rotating free-disk model with Dorfman empirical solutions is developed to evaluate the heat transfer performance considering various factors.Specifically,the influence of compressibility,variable properties,and heat dissipation is determined using theoretical and numerical analyses.In particular,a novel combined solution method is proposed to simplify the complex heat transfer problem.The results indicate that the heat transfer performance of a free disk is primarily influenced by the rotating Mach number,rotating Reynolds number,Rossby number,and wall temperature ratio.The heat transfer temperature and Nusselt number of the free disk are strongly correlated with the rotating Mach number and rotating Reynolds number.Analysis reveals that heat dissipation is a critical factor affecting the accurate evaluation of the heat transfer performance of the turbine disk.Thus,the combined solution method can serve as a reference for future investigations of flow and heat transfer in high-speed rotating turbine disk cavity systems in aero-engines.
基金National Basic Research Program of China (2007CB707701)National Natural Science Foundation of China(51106124)Research Fund for the Doctoral Program of Higher Education of China (20100201120007)