Stall Warning Indicator
Patent 16060/TUB

The invention enables the prediction of instability in a compressor, which allows an early warning in the event of a fault. The early warning system can be used in thermal turbomachinery, for example in aircraft engines.

  1. Determining the surge line without exceeding it --> non-destructive measurement
  2. Disturbances can be clearly identified and quantified
  3. Indication of last stable operating point before potential stall possible
Possible Applications

The method can be applied to thermal turbomachines such as axial or radial compressors, whereby axial compressors represent a central component in aircraft engines.


Performance data of newly developed compressors are so far measured on a test bench and then transferred to a characteristic diagram. An essential component of such a characteristic field is the so-called surge limit, since this is essential for ensuring safe operation. Exceeding the surge limit will result in instabilities, causing extremely high aerodynamic loads to the compressor that may result in considerable structural damages. However, since the surge line on the test bench can only be identified if it has already been exceeded, so far costly complete failures of the tested compressors are accepted.

It is thus an object of the invention to provide a method for determining an indicator for a prediction of instabilities in a compressor, which reliably allows an early warning of the possible occurrence such instabilities, especially the achievement of the surge limit.

Technical Description

The method developed by scientists from the institute of Aerospace Engineering is an early warning system for compressor instabilities. According to this method the compressor on a test bench is gradually been moved to its surge limit. During this process high-resolution pressure measurement is performed and the collected data can be used to calculate a specific integral parameter. If this parameter is afterwards subsequently plotted over all measured operating points, one can obtain a secure possibility of predicting the operating limit and thus the surge limit, enabling a due detection of burner instabilities. Functionality and potential of the novel method where successfully investigated using a newly built miniature single-stage low speed axial compressor at an test stand of the respective field of the TU Berlin.

Contact Us

Ina Krüger

Technology Transfer Manager

+49 (0)30 314-75916

Technology Readiness Level

Technology demonstrated in relevant environment

Property Rights

approved: CN, DE, FR, GB, IT, PL, SE, US

Patent Holder

Technische Universität Berlin

Possible Cooperation
  • R&D Cooperation
  • Licensing
  • Patent Purchase