Indian Journal of Engineering & Materials Sciences

Open Access Open Access  Restricted Access Subscription Access

Finite element analysis and optimization of active magnetic bearings for contrarotating coaxial rotor system


Affiliations
1 Department of Mechanical Engineering, National Institute of Technology Kurukshetra, Haryana 136 119, India

This paper presents the design, analysis and optimization of Active Magnetic Bearings (AMBs) to support the inner rotor in a contra-rotating coaxial rotor system. An FEM based rotordynamic model is developed using 8-dof Timoshenko beam elements assuming both inner and outer rotors to be flexible. The dynamic response of this system due to an unbalanced force is used in one of the constraints of a multi-objective genetic algorithm for controlling the vibration amplitude within 10% of the air gap. A maximum reduction of 46.9% in the amplitude peak is obtained under the present conditions. Hence, this work also offers a tool useful in touch-down bearing design. The PD controller gains are found to govern the stiffness and damping properties of the AMB. On increasing the mass unbalance by a factor of 2.5, number of turns, pole width and maximum current are found to increase by 52.9%, 29.4% and 71.67% respectively.
User
Notifications
Font Size

Abstract Views: 86




  • Finite element analysis and optimization of active magnetic bearings for contrarotating coaxial rotor system

Abstract Views: 86  | 

Authors

Shashank Shekhar Singh
Department of Mechanical Engineering, National Institute of Technology Kurukshetra, Haryana 136 119, India

Abstract


This paper presents the design, analysis and optimization of Active Magnetic Bearings (AMBs) to support the inner rotor in a contra-rotating coaxial rotor system. An FEM based rotordynamic model is developed using 8-dof Timoshenko beam elements assuming both inner and outer rotors to be flexible. The dynamic response of this system due to an unbalanced force is used in one of the constraints of a multi-objective genetic algorithm for controlling the vibration amplitude within 10% of the air gap. A maximum reduction of 46.9% in the amplitude peak is obtained under the present conditions. Hence, this work also offers a tool useful in touch-down bearing design. The PD controller gains are found to govern the stiffness and damping properties of the AMB. On increasing the mass unbalance by a factor of 2.5, number of turns, pole width and maximum current are found to increase by 52.9%, 29.4% and 71.67% respectively.