Munich Experimental Rotor Investigation Testbed
MERIT is a rotor test rig designed for universal rotor and propeller investigations. Its robust and compact design allows for highly dynamic load applications, such as fast forward flight conditions. It is designed for use in TUM´s Windtunnel A at the Chair of Aerodynamics and Fluid Mechanics.
Performance Data
| 3000 RPM |
| 85 kW |
| 270 Nm |
| +/- 30° pitch (collective + cyclic) |
| 1,2,4 blades |
| 2.6 m rotor height |
Measurement Equipment
| Inductive telemetry: 34 ch., 20 kHz p. ch., 16 bit, MANNER (strain gauges, instationary pressure sensors) | |
| DIC/Photogrammetry: ARAMIS SRX 1600 MV4200 HD 1000 Hz (blade deformation) | |
| Rotating FBG system: FBG-Scan 80X, 8 optical ch., 250 Hz p. ch. (blade deformation) | |
| 4 load cells K3D120, ME Meßsysteme (integral rotor loads) | |
| 1 torque & speed sensor DATAFLEX32, KTR | |
| 1 rotor speed sensor IH150, Globalencoder | |
| 4 pitch hall sensors PMIS4-20-40, ASM |
The Digital Image Correlation equipment and methodology was adapted and implemented to suit the AREA blade set, and both the MERIT and the AREA blades were pushed into static stall regimes. The effect of stall on the blade deformation of the different blades was investigated and published.
AREA: 500-900 rpm, 0°-18° collective pitch
MERIT: 900-1500 rpm, 0°- 24° collective pitch
=With the great support of Gunter Sanow and Daniel Maraite of the GOM GmbH we successfully performed Digital Image Correlation (DIC) tests with the ARAMIS SRX sensor at a maximum frame rate of 1000Hz to retrieve the MERIT blade´s deformation rotating with 900 and 1800rpm and up to 12° collective pitch (09-2021).
As a baseline rotor for dynamic stall experiments, the blades have no twist, a rectangular planform, naca0012 airfoil, 130mm chord and a radius of 900mm.
The structure consists of a carbon c-spar with lead balance weight and a bearing laminate with two bolts at the attachment. An integrated connector will provide the necessary interface for possible metrology such as strain gauges or pressure transduces.
We have used SONATA, VABS and ANBA4 for the predesign of the sectional properties. The first static structural tests were recently performed with the goal to verify the predicted beam properties experimentally with Digital Image Correlation (DIC)
Without the large assistance of Daniel Maraite of GOM, who supported us with an ARAMIS SRX sensor, and the continuous support of VABS from Analyswift this work would not have been possible.
We would also like to thank the TUM Laboratory for Product Development and Lightweight Design, the TUM Chair of Carbon Composites and the TUM Workshop of the Physics Department for their generous support!
Heuschneider, V., Yavrucuk, I., and Hajek, M.: Structural Blade Loads on a Rotor during Dynamic Stall in Hover, Proceedings of the Vertical Flight Society`s 80th Annual Forum & Technology Display, Montréal, Québec, Canada. May 7-9, 2024.
Baldan, G., Heuschneider, V., Mitropoulos, M., Yavrucuk, I., and Guardone, A.: Numerical and Experimental Investigation of Stall on the MERIT Rotor in Hover, Proceedings of the Vertical Flight Society`s 80th Annual Forum & Technology Display, Montréal, Québec, Canada. May 7-9, 2024.
Mitropoulos, M., Heuschneider, V., Barth, A., and Yavrucuk, I.: Experimental Whirl Tower Tests Approaching and Surpassing Stall for a Variety of Tip Speeds and Rotor Blades, Proceedings of the Vertical Flight Society`s 80th Annual Forum & Technology Display, Montréal, Québec, Canada. May 7-9, 2024.
Berghammer, F., Sosa, B., Heuschneider, V., Yavrucuk, I., and Hajek, M.: Testing of a Fiber-Optical Sensor System for Rotor Blade HUMS, Proceedings of the Vertical Flight Society`s 79th Annual Forum & Technology Display, West Palm Beach, Florida, USA. May 16-18, 2023.
Heuschneider, V., Berghammer, F., Abdelmoula, A., Hajek, M., and Sirohi, J.: Model Based Blade Attachment Stiffness Evaluation of the MERIT Rotor in Hover with Photogrammetry and Digital Image Correlation, Proceedings of the Vertical Flight Society’s 78th Annual Forum & Technology Display, Fort Worth, Texas, USA. May 10-12, 2022.
Berghammer, F., Heuschneider, V., and Hajek, M.: Development And Integration Of A Fiber-Optical Sensor System For Rotor Blade State Observation, Proceedings of the Vertical Flight Society’s 78th Annual Forum & Technology Display, Fort Worth, Texas, USA. May 10-12, 2022.
Heuschneider, V., Berghammer, F., Pflumm, T., and Hajek, M.: Development and Initial Hover Testing of the Mach Scaled Rotor Test Rig MERIT, Proceedings of the 47th European Rotorcraft Forum, Royal Aeronautical Society, Virtual, September 2021.
Pflumm, T., Gaugelhofer, L., Heuschneider, V., Berghammer, F., and Hajek, M.: Hybrid Experimental Measurement of Sectional Stiffness Properties of the MERIT Rotor Blade with Digital Image Correlation, Proceedings of the 47th European Rotorcraft Forum, Royal Aeronautical Society, Virtual, September 2021.
Heuschneider, V., Berghammer, F., and Hajek, M.: Numerical and Experimental Study on the Modal Characteristics of a Rotor Test Rig, Society for Experimental Mechanics, Topics in Modal Analysis & Testing, Volume 8, Proceedings of the 38th IMAC, A Conference and Exposition on Structural Dynamics 2020.
Matti Mitropoulos, M.Eng. (Test rig operation, rotating DIC/photogrammetry system)
Verena Heuschneider, M.Sc. (Test rig design, instrumentation & operation, dynamic stall campaigns)
Tobias Pflumm, M.Sc. (Rotor blade composite design & manufacturing)
Florian Berghammer, M.Sc. (FBG sensor integration, rotating blade deformation)