Research Group

Combustion Dynamics

Optimal optical access
Larger windows with curvature allow a better view of the process inside the combustion chamber.
Credit:

DLR

DownloadDownload

The Combustion Dynamics group deals with combustion dynamics processes in rocket combustion chambers. This includes the experimental investigation of propellant injection into the combustion chamber, the ignition process and the experimental investigation and modeling of combustion instabilities in combustion chambers.

Fuel injection significantly influences the stabilization of the combustion zone in the combustion chamber and thus the efficiency of an engine. Experiments and numerical simulations are used to analyze the flow dynamics within injection elements and the interaction of the inflow properties with combustion.

Combustion dynamics in a rocket combustion chamber
The combustion process inside a combustion chamber gives the rocket the thrust for its journey into space. The dynamics of the flame play an important role here: they influence the performance and reliability of the combustion chamber.

In the field of ignition of rocket combustion chambers, the effects of start-up sequences on the ignition process as well as new ignition systems and methods, such as laser igniters, are being developed and tested.

Work on combustion instabilities focuses on the interaction of acoustic oscillations with combustion. The dynamic processes are recorded quantitatively in research combustion chambers. Using specially developed measurement techniques and data evaluation algorithms, details of the energy transfer from combustion to acoustics are elucidated. Numerical simulations support the interpretation of the observed processes.

Video: DLR develops new research combustion chamber
A research combustion chamber with large windows developed at the German Aerospace Center (DLR) provides new insights into a little-discovered world: the interior of a rocket combustion chamber. The processes that take place there are fundamental for successful missions into space. If the fuel does not burn stably, the engine can be severely stressed and destroyed within seconds. At the heart of the research combustion chamber is a unique optical access system that DLR researchers have developed in recent months.

For the experimental investigations, tests are carried out with test combustion chambers and igniter prototypes, for example with the help of the modular research combustion chamber "N", which enables tests with up to 100 bar combustion chamber pressure and optical access to the combustion chamber.

These tests take place at the technical center M3.1 and the research and technology test bench P8 of the DLR Institute of Space Propulsion in Lampoldshausen. The following services are provided by the Combustion Dynamics Group:

  • Characterization of injector elements by cold gas tests as well as by tests under representative operating conditions,
  • Characterization of ignition technologies, ignition sequences and strategies under representative operating conditions,
  • Combustion dynamic stability analysis of combustion chambers in the pre-design and during the test and development phase,
  • Consulting on high and low frequency stability problems during combustion chamber operation,
  • Acoustic measurement of rocket combustion chamber volumes as well as testing and evaluation of damping technologies.

Kontakt

Dr. Justin Hardi

Head of Department
German Aerospace Center (DLR)
Institute of Space Propulsion
Rocket Propulsion Technology
Im Langen Grund, 74239 Hardthausen
Germany