A Piezoelectrically-Actuated Valve for Modulation of Liquid at High Flow Rate Under High Pressure

A MEMS valve implementation is presented as part of a comprehensive liquid fuel modulation system that targets improved NOx emissions in gas turbines. The target metrics require fuel delivery at high flow rates (>10 ml/s) and bandwidths (>100 Hz) against high pressures (>75 psi). A prototype microvalve has been designed and fabricated with conventional micromachining techniques coupled with an off-the-shelf piezoelectric actuator. The device has dimensions of 40 mmtimes11 mmtimes2.5 mm. Test results demonstrate flow modulation of 15 ml/min at 20 psid and 50 Hz, when the applied sinusoidal voltage to the piezo actuator and therefore the orifice area modulated by the lever arm, was varied between 84 V to 120 V.