[Master Thesis] Study of Rotating Detonation Combustor Injectors: Operational Stability and Per[...]

Stellenbeschreibung:

Pressure Gain Combustion (PGC) has become a focal point in reactive fluid mechanics, as researchers aim to leverage the theoretical efficiency improvements it offers for next-generation propulsion and gas turbine cycles. Among these technologies, the Rotating Detonation Combustor (RDC) (Nassini, 2021: is particularly promising. While the theoretical potential for pressure gain is well-established, experimental verification remains a significant challenge (Bach et al., 2021:

At TU Berlin, the RDC consists of an annular chamber where a detonation wave is ignited and propagates circumferentially. At the base of the chamber, the injector geometry drives the mixing of hydrogen and air. This component is currently the primary source of total pressure loss within the system and must be optimized to balance mixing efficiency with operational flexibility. The detonation process generates extreme temperature and pressure gradients, leading to complex compressibility effects—such as shocks, reflections, and parasitic deflagrations—which can destabilize the wave and hinder performance.

This Master Thesis focuses on testing new pintle injector geometries with varying air-injection-to-combustion-chamber area ratios. Increasing this ratio is hypothesized to be a key driver in achieving net pressure gain. The student will commission a new set of injectors and conduct an extensive experimental campaign. By varying mass flow rates and equivalence ratios, the student will map the stability limits of each geometry (Bluemner et al., 2020: using high-frequency dynamic pressure measurements (Wei et al., 2025: Furthermore, static and total pressure/temperature data will be synthesized to evaluate thermal efficiency and quantify pressure gain.

The conclusions drawn from this work will establish a direct correlation between area ratios and injector performance, providing critical guidance for the optimization of RDC architectures.

Scope of Work

Literature Review: PGC, RDC stability, and injector dynamics.
Commissioning: Installation of hardware into the TU Berlin RDC rig.
Experiments: High-pressure and energetic facility operation; mass flow and equivalence ratio variation; high-frequency data acquisition; pressure and temperature sensors.
Data Analysis: Detonation mode identification; Study of stability limits; Thermal efficiency and pressure gain computation.
Comparative Study: Assessing area ratio impact on RDC operation.
Stability Maps: Assess RDC behavior per geometry.
Performance: Compare critical metrics and conclude on area ratio impact
Master Thesis: Final document with methodology, results, and future design guidance.
Data Archive: Organized experimental datasets and analysis scripts.