MEMS Jet Fuel Atomizer

Future aircraft will require highly efficient propulsive power plants to achieve their performance goals. Improvements in gas turbine combustion are needed; particularly broader flammability limits and reduced emissions. Fuel injection, both atomization and distribution, is critical for stable flameholding and complete combustion. Undesirable emissions largely stem from unburned fuel and high temperature zones created by poor atomization and mixing. Unfortunately, current atomizers produce a droplet distribution that has an unacceptably large number of big droplets up to 200 microns even though the Sauter-mean diameter can be as small as 30-40 microns. Therefore, TDA Research, Inc., teamed with the University of Colorado-Boulder, proposes a novel self-aspirated MEMS atomizer based on the principles first used in inkjet atomization. A MEMS atomizer can produce monodisperse droplets smaller than 50 microns with very little pressure drop. The atomizer will be designed to operate in JP-8 fueled gas turbine engines. In Phase I we will predict atomizer performance, design and fabricate prototype MEMS atomizers, and conduct spray atomization tests in a windowed dump combustor. In Phase II we will design large array atomizers, conduct CFD analyses, construct prototypes and integrate them into a laboratory scale turbine for combustor testing.