Application of Switching Valves to Improve Reliability of Fueldraulic Systems

DynSan will collaborate with the Purdue University to develop and test an innovative, fast digital hydraulic valve design that is insensitive to working fluid contamination. The goal is to improve the reliability of fueldraulic systems on aircraft gas turbine engines and similar applications. Current fueldraulic systems use flapper-type Electro Hydraulic Servo Valves (EHSV) to control actuator position. We propose to develop a new generation of digital EHSVs that does not suffer from the common problems experienced by the flapper-type designs such as stiction, null bias shift, and flapper damage. The new design uses an ensemble of appropriately controlled simple switching valves to digitally control an actuator. Phase I simulation and benchtop experiment results show that the new design exhibits excellent response characteristics in comparison to flapper-type EHSVs, and is insensitive to contamination. Phase II will develop a working hardware prototype and will have four focus areas: 1) updating of theoretical design tools developed in Phase I; 2) virtual prototyping, optimization and packaging of new design; 3) manufacturing and testing of a valve prototype; and 4) comparing the performance of the new digital approach to that of the currently used flapper-type valve design. Follow-on research will test the new valve on a wet rig simulator at Navy facilities. Phase III commercialization will seek to exploit the natural multi-use applicability of the developed system.