This paper proposes a control approach that can provide significant energy savings for the control of pneumatic servo systems. The control methodology is formulated by decoupling the standard four-way spool valve used for pneumatic servo control into two threeway valves, then using the resulting two control degrees of freedom to simultaneously satisfy a performance constraint (which for this pa...

Design models of multi- stage, axial flow compressor are developed for gas turbine engines. Axial flow compressor is one of the most important parts of gas turbine units. Therefore, its design and performance prediction are very important. One-dimensional modeling is a simple, fast and accurate method for performance prediction of any type of compressors with different geometries. In this appro...

This paper deals with the achievement of a reduced order mathematical model using the singular perturbations method for an electrohydraulic system composed by a hydraulic cylinder which is controlled with an electrohydraulic servovalve with five ways. Due to the high value of the bulk-modulus of fluid, to the low value of the fluid occupied volume and also to the spool valve mass low, the equat...

Active self-assembly, in which non-thermal energy is consumed by the system to put together building blocks, allows the creation of non-equilibrium structures and active materials. Microtubule spools assembled in gliding assays are one example of such non-equilibrium structures, capable of storing bending energies on the order of 10(5) kT. Although these structures arise spontaneously in experi...

ion The hiding operator P n A makes the events in the set A internal to the process, thus removing them from the control of the environment. The only participants will then be the components of P. From the maximal progress assumption, the internal events will occur as soon as P is ready to perform them. In general, internal events occur as soon as they are ready, unless they are pre-empted beca...

In this paper, a sensorless method of detecting the spool position high-speed on/off solenoid valve is presented. The depends on analyzing time-current curve coil passing current and measuring maximum stroke spool, such that dynamic behavior estimated displacement plotted. A mathematical model developed effect hydraulic force studied. Experimental results show proposed error less than 7% when c...

the aim of this study is designing the impeller of a centrifugal compressor in order to supply pressure ratio for a 65 kw micro gas turbine. first, the primary thermodynamic analysis has been conducted for the considered cycle using a home made code. herein, the compressor pressure ratio was considered to be 4. the obtained thermal efficiency was 25.64%. then, the design of micro compressor in ...

Since conventional crank-driven compressor had many difficulties to increase efficiency due to mechanical loss, new kind of compressor has been paid much of attention by the compressor manufacturers. The free piston compressor mechanism has been one of those kinds. The compressor manufacturers developed an energy efficient free piston linear resonance compressor for a household refrigerator. In...

When a thin sheet of a flexible material such as paper is fed from a horizontal spool towards a rough horizontal plane below it, the sheet folds on itself in a regular manner. We model this phenomenon as a free boundary problem for a nonlinearly elastic sheet, taking into account the stiffness and weight of the sheet and the height of the spool above the plane. By using a continuation scheme we...