FE Approach: Role of Fluid properties in Actuator Dynamics

This paper gives a new approach for fluid-structure interaction of servovalve component actuator using finite element method. FE approach gaining a more advancement in dynamic analysis of structural components. For fluid flow analysis, computational fluid dynamics software's like fluent were frequently used. The fluid-structure interaction is challenging issue in finite element field. An attempt has been made to interact hydraulic component piston and cylinder with fluid using special purpose hydrostatic fluid elements along with general-purpose solid elements. The positioning of piston depends upon the flow rate from control ports and the amount of load to be moved. In this paper an emphasis was made on actuator dynamics for different fluid property. The fluid property like fluid bulk modulus, expansion coefficient plays the major role in all type of hydraulic components. Bulk modulus of fluid changes drastically due to the entrapment of air bubbles in the fluid. The fluid cavities were modeled with special purpose hydrostatic fluid elements. Hydrostatic fluid elements are surface elements that cover the boundary of the fluid cavity. Natural frequency of the actuator was depends upon the position of piston in the cylinder and was studied for different piston position.