Transonic cascade wind tunnel (TGK)

The transonic cascade wind tunnel (TGK) is installed at the Institute of Propulsion Technology in Cologne. This large-scale facility is used for investigations on compressor blade cascades; it is the world's only such facility that allows inflow Mach numbers of up to 1.4, whilst simultaneously enabling independent variation of the Reynolds number.

The TGK at German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is also unique due to its extremely stable test conditions, especially at the speed of sound. Among other things, this is made possible by the continuous closed-loop operation of the tunnel. In addition, the aerodynamic load (AVDR) acting on the investigated cascades can be controlled with great precision due to the high extraction capacities.

Aerodynamics of compressor blade cascades

The TGK is used for fundamental research into the aerodynamics of compressor blade cascades. It enables the assessment of the load and loss behaviour of the cascades. Due to its excellent accessibility for measurements, the TGK is used to test prototypes of new measurement methods. In addition, the facility can generate highly precise experimental data that is used for the validation of numerical simulations.

Due to its focus on fundamental research, the TGK serves as a link between theoretical research findings and their applications. Such applications include highly complex, experimental testing currently being completed on a rotating compressor rig at the Multistage Two Shaft Compressor Test Facility in Cologne. The facility enables the performance of highly precise, detailed measurements of individual flow phenomena, thus allowing a more profound analysis of flow effects.


Volker Speelmann

Head of Research Infrastructures
German Aerospace Center (DLR)
Executive Board department for Innovation, Transfer and Research Infrastructure
Linder Höhe, 51147 Cologne

Dr.–Ing. Alexander Hergt

German Aerospace Center (DLR)
Institute of Propulsion Technology
Fan and Compressor
Linder Höhe, 51147 Cologne