Low Speed Open Jet

The low speed open jet wind tunnel at the Institute of Turbomachinery and Fluid Dynamic can be used for various aerodynamic and aeroacoustic investigations. The measurement section is built as a modular unit, so that different types of test samples can be placed and studied with respect to their aerodynamic and acoustic properties. 

Field of Application

  • Investigation of the aeroacoustic formation mechanism of different test objects in a flow
  • Aerodynamic investigation of test objects in an open jet
  • Testing and optimization of acoustic and aerodynamic measurement technologies
  • Development and testing of aeroacoustic measurement and analysis methods
  • Validation of numerical simulation models (CAA)


Currently, the test rig is used for the joint research project Smart Blades. In the project, detailed aeroacoustic and aerodynamic investigations are performed on a scaled airfoil with a trailing edge flap in the open jet. The main foci of the current study are the higher global sound emission of the flapped airfoil, the sound formation at the side edge of the flap and also the relationship between sound formation and characteristic flow parameters.

In addition, the test rig is used to enhance measurement instrumentation, techniques and algorithms. As an example, the established beamforming technique is improved in terms of higher order solutions and computational time. Furthermore, a completely robot-supported measurement of an open jet is tested, to decrease expensive measurement time and save measurement resources.

Picture - Low speed open jet - total view Picture - Low speed open jet - total view Picture - Low speed open jet - total view
Low speed open jet - total view
Picture - Measurement section Picture - Measurement section Picture - Measurement section
Measurement section

Measurement Techniques

  • Microphone measurement instrumentations to determine sound pressures
  • Acoustics camera to localize sound sources
  • Steady and unsteady pressure instrumentation
  • CTA / CCA sensors to detect flow vectors and the turbulences of the flow


Maximal Reynolds-Number Remax 0,4x105 bei d=300 mm
Large, useable core flow of the open jet Acore 9.600 cm2
Modular measurement section (variable implementation of test objects)
Option of a completely automatic robot-supported aerodynamic measurement