A team of researchers funded by NASA has made a breakthrough in hypersonic flow technology, enabling operators to manage airflow at the speed of light during the dangerous “shock train” condition. Shock trains precede engine failure in scramjet engines and now, for the first time, University of Virginia School of Engineering and Applied Science researchers have shown that optical sensors instead of pressure sensors can be used to monitor airflow through a supersonic combusting jet engine.
This advancement offers engineers of hypersonic scramjet propulsion engines new ways to maintain engine performance when shock trains are detected. Aircraft traveling above Mach 5, or five times the speed of sound, are classified as “hypersonic.”
Professor Christopher Goyne, director of UVA’s Aerospace Research Laboratory, explained that since hypersonic aircraft operate at such high speeds, it made sense to use sensors operating closer to the speed of light rather than the speed of sound for monitoring airflow.
The team noted that 20 years ago, NASA’s experimental X-43 “Hyper-X” aircraft reached hypersonic velocities, but its monitoring and control technology was based on older pressure sensor technology. Hypersonic engines require the continuous flow of supersonic air through them. Traditional pressure sensors operating at the speed of sound provided limited information about engine states.
After several hours of testing, the team discovered that by sensing light spectra (specifically), they could indeed spot conditions leading up to unstart(shock train) conditions. Using optical sensors to analyze light spectra(across all three parameters) allowed them to detect and counteract shock trains before the unstart event occurred.
The light emitted by reacting gasses in the engine combustor(specifically) was crucial, enabling the team to monitor and control theconditions within thescram
“Combined, The Team’s Experience”
“The Team’s Progress”
“A New Approach:OpticalSensors inHyperson>
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Source: https://thedebrief.org/nasa-funded-hypersonic-breakthrough-can-eliminate-deadly-shock-train-at-the-speed-of-light/