High Frequency Surface Pressure, Shear Stress and Heat Flux Measurements for High Temperature Applications

The proposed optical fiber-based heat flux sensors possess many of the desired performance features for high-speed, high-temperature heat transfer studies for future Air Force hypersonic ground- and flight-test programs.  During Phase I, motivated by the demand for robust instrumentation for aerodynamic heat transfer studies, Lambda Instruments, Inc., in cooperation with the Aerospace Engineering Department at Virginia Tech and Vatell Corporation, successfully demonstrated the feasibility of a new optical fiber-based heat flux sensor.  The salient features of the prototype sensor include extremely high-temperature capability (approximately: 1273 K using silica fiber, 2323 K using sapphire fiber), small size (diameter 100 kHz).  Based on Phase I theoretical and experimental results, the development team strongly believes that the current and projected performance features of the prototype sensor make it a strong candidate for continued development in Phase II and eventual commercialization. BENEFIT: In addition to the current Air Force heat flux sensor application Lambda foresees significant commercial market possibilities for such devices in industry and fire research, meteorology and soil, broadband radiology, building physics, and material science.  Lambda proposes to investigate commercial development strategies for advanced high-temperature optical fiber heat flux sensors with Vatell Corporation. Lambda and Vatell envision a ready market for the proposed optical fiber-based heat flux sensors, primarily because of their potential to operate up to the 2000° F melting point of silica fiber and potential low cost.