Researchers at the Karlsruhe Institute of Technology (KIT) have set a new endurance record for a compressorless hydrogen gas turbine, running it for 303 seconds — more than five minutes — and beating the previous 250-second record held by NASA.

The turbine uses pressure-gain combustion: detonation waves generated inside the combustion chamber produce the high pressure needed for combustion, eliminating the mechanical compressor that conventional gas turbines rely on. In a standard gas turbine, compressing air consumes about 50 percent of the engine's power — energy that never reaches the generator or propeller.

"This is an important step toward highly efficient and flexible hydrogen energy for a fossil-free energy system," said Professor Daniel Banuti, Director of KIT's Institute of Thermal Energy Technology and Safety (ITES). Earlier experiments could only run for fractions of a second before the combustion chambers melted; the KIT team also became the first to generate electricity from a compressorless hydrogen turbine earlier this year.

Hydrogen is especially well suited to the design because it reacts quickly and produces stable pressure increases, though the system can run on other fuels as well. Removing the compressor could lead to lighter, cheaper and more efficient turbines — for electricity generation today and, potentially, aviation in the future.

"The very fast and intense combustion processes in the chamber make stable energy transfer to the turbine challenging," Banuti said. "We are the first to successfully operate such a turbine and generate electricity in the process."

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