MEMS Fluidis Vortex Valves for Gas Turbine Fuel Control Systems

We proposed to develop enabling technology for the digital control engine fuel (turbine, diesel, etc.) by using a large array of very fast acting, micro-miniature (MEMS technology), fluid, tab-actuated, vortex valves. Such valving technology would, for the first time permit active control/modulation and digital waveform synthesis of engine liquid fuel flow, with specific application to the active control of combustor instabilities in military and commercial gas turbines. Most conventional macro-size valves are not sufficiently responsive, and those that are, are very expensive due to the need for close tolerances and exotic materials, and have poor reliability due to the mechanical complexity. DRT's MEMs valves, operated by a simple, unloaded, vortex-tripping tab, are based on a macro-sized version demonstrated, in high speed mud pulse telemetry systems, and can modulate flow by more that 3:1. MEMs tab motion would be achieved by using a on-chip electro=static comb actuators, and possible, when they are developed, NASA Thunder, low voltage, piezo-electric benders. These benders will demonstrate the capability to design and manufacture micro-miniature vortex valves with a flow modulation capacity of 10 percent of a typical engines fuel flow. By etching arrays of valves in silicon with and without projecting tabs the limits of modulation will be established. Testing with water and kerosene will validate CFD projections which will have been performed to analyze the low Reynolds number vortex flow fields. Analysis of the actuation system to be designed in Phase II will also be conducted.