DLR Portal
Home|Sitemap|Contact|Accessibility Imprint and terms of use Privacy Cookies & Tracking |Deutsch
You are here: Home:Departments and Groups:Combustion Diagnostics
Advanced Search
Key Research Topics
Departments and Groups
Chemical Kinetics and Analytics
Computer Simulation
Gas Turbines
Combustion Diagnostics
Multiphase Flow and Alternative Fuels
High-pressure Experiments
Research Facilities
Projects
Publications
Job Opportunities
Press Release
How to find us
Print

Combustor Systems and Diagnostics



 Temperature measurement with CARS in a spray flame
zum Bild Temperature measurement with CARS in a spray flame

Advanced laser-based measurement techniques provide new insights into physicochemical combustion processes. These techniques can visualise flame structures, detect flow relations in the combustion chamber, and can measure how the concentrations of combustion-relevant species are distributed and what temperatures are present. This requires a variety of diagnostic methods which mutually complement each other and are based on different physical processes. Unlike physical probes, these optical techniques permit the analysis of flames without influencing either the flow field in the combustion chamber or the complex chemical reactions that occur. Laser-based measurement techniques operate non-intrusively, with a high spatial and temporal resolution, and as light sheet techniques can also measure two-dimensional distributions. These techniques are mainly applied as single-pulse techniques, i.e. a full measurement is performed with each single, extremely short laser pulse. These are essential requirements for resolving the turbulent structures in the combustion zones and for obtaining precise and accurate information about the combustion process. Quantitative measurement data provide the experimental basis for testing and improving numerical simulation models, which nowadays are indispensable for improving the assessment of newly-designed combustion processes with respect to pollutant emissions and stability of the combustion process.

The workgroup mainly focuses on developing laser measurement techniques to address a wide range of combustion research issues.

Advancing laser-based measurement methods

The laser-based measurement methods detailed below are continuously being developed in order to adapt them to measurement requirements under special boundary conditions, including technical conditions, such as high pressure and real fuels.

  • Rayleigh scattering (density and temperature fields)
  • Raman scattering (temperatures, concentrations, mixtures)
  • Coherent anti-Stokes Raman scattering (CARS) (temperature measurement in technical combustion systems, mean values and fluctuations using single-pulse technique)
  • Absorption spectroscopy (Measurement of species concentrations and temperatures)
  • Laser-induced fluorescence (LIF) (visualisation of flame structures, position of flame front, 2D temperature fields)
  • Laser-induced incandescence (LII) (2D soot distributions)
  • Particle image velocimetry (PIV) (2D velocity distribution)
  • Simultaneous use of different measurement techniques
  • High-speed imaging (LIF and PIV)
  • Laser-induced plasma spectroscopy (LIPS) (Measurement of elementary composition or minority species)
  • Phosphor thermometry (Determination of surface temperatures))
  • Mobile laser-based measurement systems (Raman, CARS, LIF, LII)

Applications to technical systems

Outside the laboratory, the various measurement techniques are used in applications-based technical systems, and specifically to gas turbine combustion chambers. Experiments on such measurement objects are carried out on the Institute’s high-pressure test rigs or on site for customers. The mobile measurement systems mentioned above are available for this purpose. Successful measurements have been carried out on

  • segments of gas turbine combustion chambers
  • industrial gas turbine burners
  • model combustors for rocket propulsion units
  • industrial combustion systems
  • close-to-production engines
  • gasifiers

Priority research areas

In addition to improving methods and applying them to technical objects, the workgroup also addresses a number of issues in basic research. This work centres on improving our basic understanding of the combustion process being studied, such as soot formation in high-pressure combustion chambers, combustion behaviour of alternative fuels, ignition processes or combustion instabilities under special operating conditions such as lean premix combustion. Work is also being done to provide an extensive data basis for validation and improvement of numerical simulation models. To this end, standard flames are defined that are then studied using laser-based diagnostic methods.

Additional information about these standard flames can be found in the data archive of the Institute of Combustion Technology.


Contact
Dr. Klaus-Peter Geigle
Abteilungsleiter Brennersysteme und Diagnostik

Deutsches Zentrum für Luft- und Raumfahrt (DLR)
, Institut für Verbrennungstechnik
Stuttgart

Tel.: +49 711 6862 398

Fax: +49 711 6862-578

Dr. Oliver Lammel
Abteilungsleiter Brennersysteme und Diagnostik

Deutsches Zentrum für Luft- und Raumfahrt (DLR)
, Institut für Verbrennungstechnik
Stuttgart

Tel.: +49 711 6862 572

Mobile: Oliver.Lammel@dlr.de

Fax: +49 711 6862-578

Research Fields
Development of methods
Sooting flames
Thermoacoustics
Alternative fuels
Standard flames
Gas turbine combustion
Applications
Equipment
Links
DLR-Workshop on Diagnostics in Combustion and Aerodynamics (DIVA)
List of Publications
Related Topics
Atomic and Molecular Physics
Copyright © 2022 German Aerospace Center (DLR). All rights reserved.