Harsh-Environment Sensors for In-Flight Hypersonic Engine Tests

MesoScribe has developed a suite of sensors suited to measuring mechanical and flow properties in harsh environments, such as hypersonic air-breathing propulsion systems. The sensors have been previously demonstrated in airborne and industrial gas turbines, exposed to high temperatures, pressures and g-loading. Using proprietary Direct Write fabrication, a high-precision derivative of thermal spray technology, MesoScribe has the capability to manufacture multilayer sensors, circuit elements, antennas and interconnects directly onto engineering components without clean rooms, lithography or post-processing. The devices produced boast low mass, low profile, high adhesion and high temperature operability. Direct write strain gages are proposed for monitoring duct geometry and flow area. Thermocouples and multilayer thermocouple arrays can measure wall temperature and heat flux, respectively. Thermal-based sensors can measure skin friction through convective power dissipation. Distributed sensor arrays can locate shocks by identifying discontinuities in thermodynamic states within the core flow. Locating these discontinuities and quantifying changes across them further characterizes flow properties along the engine duct. Compatibility of direct-write with thermal spray enables multifunctional coatings to be produced, which comprise discrete sensor layers embedded within thermal barrier or ablative coatings. The flexibility of direct-write allows sensors to be fabricated onto bare substrates with equivalent performance.