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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 pressure gain characteristics of jet pipe servovalve is required as an input to the designer for improving performance of the servovalve. An attempt has been made to design the first stage jet pipe servovalve parameters to get maximum pressure recovery. The static recovery pressure in receiving holes is a function of jet pipe nozzle displacement relative to receiver plate. The recovery pressure depends on web thickness, jet pipe nozzle diameter, receivers hole diameter, nozzle offset and nozzle stand-of distance. A detailed static recovery pressure analysis of a two stage, four-way, closed ports electrohydraulic flow control valve considering the effect of web thickness, nozzle diameter, receiver hole diameter and offset parameters are presented in the paper. Also the effect of supply pressure on recovery pressure is presented.

This paper presents the development of selectively reinforced metal matrix composite (MMC) piston and the associated squeeze casting facility. The need for materials with property mixes and enhanced thermal stability has focused much interest on the development of MMCs, as they offer considerable promise to automotive engineers. The benefits are many fold. The important ones include reduced weight, low thermal expansion, leading to reduced problem of engine seizure and improved wear resistance. Among the various processing methods of MMCs, squeeze casting provides several advantages such as finer microstructure, freedom from porosity, more ductility etc. A squeeze casting machine has been designed and developed, where most of the operations are automatic, except preform placing, product pickup and die cleaning. A selectively reinforced piston has been developed using this facility. The material system consists of aluminium - silicon alloy and alumina-silicate short fibre preform.

The concept of hydrostatic steering of Armoured Fighting Vehicles(AFVs) is reviewed. An approximate method for estimating hydrostatic steering power, turning radius and steering speeds is discussed. Hydrostatic steering system parameters are introduced in the estimation of steering power of AFVs. The results are presented in a graphical form. An example illustrates the use of this graph in arriving at the steering power for a given set of operating conditions.