A team of researchers financed by NASA has made a significant breakthrough in hypersonic flow technology, allowing operators to control air flow at the speed of light in the case of a dangerous “shock train”. This condition typically precedes engine failure in scramble engines, which are direct-flowing air-reactive engines.
For the first time, researchers from the University of Virginia demonstrated the possibility of controlling supersonic combustion engines using an optical sensor instead of a traditional pressure sensor. This new method enables engineers of scramjet engines, operating on hypersonic prototypes, to maintain engine performance at speeds above Mach 5 when a shock train is detected.
Optical sensors operating at the speed of light greatly improve reaction time to adverse air flow conditions compared to outdated pressure sensors that operate at sound speed. At hypersonic speeds, even a slight slowdown in air flow can cause engine “failure” when the air flow at the engine inlet drops below the supersonic threshold, resulting in a sharp decrease in thrust and complicating engine restart.
Testing and Results
The research team conducted tests at the Virginia Supersonic Laboratory, where conditions of hypersonic engines are replicated at Mach 5 speed. Through extensive testing, the team gathered significant data confirming that optical sensors can effectively detect conditions leading to shock trains by analyzing light emitted by reacting gases inside the scramjet engine.
Researchers are currently testing new sensor configurations to develop a prototype optical shock train detector for real flight testing. This progress represents a crucial step towards creating a single-stage orbital aircraft that can take off and land like a regular plane, enhancing safety, convenience, and reusability in space flights.
The accomplishments of the University of Virginia team could make a significant contribution to the advancement of safer and more efficient access to space, surpassing current technologies used in missile systems.