ResearchProject Area A
Subproject A4

Combustion Chamber Defects (finished 2017)

The aim of subproject A4 is the localization of a defect in the combustion chamber in an aircraft engine by an association between combustor errors and measured texture of the exhaust jet. Damages at the aircraft engine could be detected with appropriate exhaust jet diagnostics and allows an evaluation of the state of the engine without disassembly.


Model combustion chamber for investigations of the influence of defects

Defects in combustion chambers of aircraft engines might reduce the performance and represents an increase stress of the turbine. An exhaust jet analysis informs earlier decisions about the time and extent of the regeneration process and can help to extend the maintenance cycle. The subprojects A3 and A4 cooperate to achieve this aim. While the influences of turbine defects on the exhaust jet are investigated in subproject A3, subproject A4 focuses on the defects in the combustion chamber and their effects. For the detection of combustor defects, species concentration and emission measurement techniques will be used, which allows a comprehensive analysis of the engine and the current operating condition.


In the first funding period of the project, the feasibility and function of an exhaust gas analysis was initially demonstrated. For experimental purposes, two experimental combustion chambers were developed and put into operation. Extensive experimental investigations concerning the reference and different failure cases have been carried out. Numerical studies have already been done on real aircraft engines and the model combustion chamber to simulate the flow and reactive processes with CFD. The simulated data from the calculations were successfully validated with measurements of flow velocity and emissions within the combustion chamber. For both, numerical simulations were performed for the reference and failure cases.

Operation of the model combustion chamber with a faulty fuel supply


For the next steps, it is necessary to quantify the turbulent mixing of defect signatures in combustion chambers. The mixing reduces the information content about the position of the defect and the influence on the exhaust jet behind the engine. This limits the applicability of the defect detection with the methodology of the exhaust jet analysis. The mixing of defect signatures occurs through diffusive processes that blur temperature and gas concentration patterns. The complex diffusion is one possible approach and will be further investigated in subproject A6 with the experience gained in project A4.

Simulated CO distribution at the combustor outlet for a faulty burner operation


  • Hartmann, U.; Hennecke, C.; Dinkelacker, F.; Seume, J. R. (2016) Automatic Detection of Defects in a Swirl Burner Array Through an Exhaust Jet Pattern AnalysisIn: J. Eng. Gas Turbines Power 139 (3)
    DOI: 10.1115/1.4034449
All publications of the Collaborative Research Centre


Prof. Dr. Friedrich Dinkelacker
Welfengarten 1A
30167 Hannover
Welfengarten 1A
30167 Hannover