High-Temperature, MHz-Bandwidth, Miniaturized Heat-Flux Sensors for High-Speed Flows

The Interdisciplinary Consulting Corporation (IC2) proposes to develop high-temperature, high-bandwidth, miniaturized heat flux sensors that are applicable in a variety of environmental conditions such as those encountered in high-speed ground- and flight-test facilities.nbsp;The proposed sensing system addresses a critically unmet measurement need in NASArsquo;s technology portfolio, specifically the ability to make quantitative, time-resolved, mean and fluctuating heat-flux measurements with sufficient dynamic range, bandwidth, and spatial resolution in high-temperature, high-speed flows using a robust, miniature sensor to facilitate installation in scale models and high-speed ground- and flight-test facilities.nbsp;The sensor system will enable single-point measurement of heat flux for characterization of complex boundary layer flows in ground-test facilities over a wide range of temperatures, with a target maximum continuous operating temperature gt;1000nbsp;K (727nbsp;deg;C).nbsp; The proposed heat-flux sensor consists of a microfabricated thin-film thermopile on top of a support substrate with a thin protective coating and backside electrical connections.nbsp; This design represents a robust, flush-mounted, miniature, heat-flux sensing system that possesses improved sensor survivability, reduced humidity sensitivity, and less bulky, fragile packaging than existing solutions. nbsp;The flow disturbance for this sensor is minimal because of the flush-mount design and small footprint. nbsp;Optimized sensor electronics will also help improve the sensitivity, dynamic range, and bandwidth of the sensor.