Specialized combustion chamber enables improvements to renewable fuel engines

Low-carbon fuels such as ammonia and hydrogen are becoming promising alternatives to traditional fuels. However, standard combustion chambers are not optimized for these fuels. To improve efficiency and reduce emissions, alternative combustion systems are needed for low-carbon fuels.

Sen and Biwas designed a specialized constant volume combustion chamber (CVCC) designed to study combustion of alternative fuels at high pressures. The CVCC has two connected chambers with multiple windows which allowed researchers to see into 80% of the interior. This enables the researchers to do highly detailed studies of turbulent jet ignition chemistry by using optical techniques like Schlieren imaging, chemiluminescence, and laser diagnostics.

“One of the most exciting aspects of our work is the flexibility of our CVCC design,” said author Sayan Biswas. “It can be adapted to study a wide range of reaction and combustion processes under different conditions and with different fuels.”

The modular design allows the chamber to be adjusted to study turbulence, temperature variations, and fuel-air mixtures. Notably, the system can withstand pressures up to 1,500 pounds per square inch, enabling studies of real-world large engines, like those in power plants and natural gas infrastructure.

“By optimizing how fuels burn in these engines, we can make existing infrastructure significantly cleaner while the world transitions to more sustainable energy sources,” Biswas said. “The insights gained from this study could also help in the design of future engines that can operate efficiently on a range of low-carbon fuels.”

The authors plan to use the CVCC to study several different renewable fuels as well as collaborate with engine manufacturers to develop next-generation combustion systems.

Source: “Optical prechamber-equipped high-pressure large-bore optical combustor for fundamental combustion studies,” by Daipayan Sen and Sayan Biswas, Review of Scientific Instruments (2025). The article can be accessed at https://doi.org/10.1063/5.0245692 .