MARHy Wind Tunnel


The MARHy Hypersonic low density Wind Tunnel, located at the ICARE Laboratory in Orléans, France, is a research facility used extensively for fundamental and applied research of fluid dynamic phenomena in rarefied compressible flows. Its name is an acronym for Mach Adaptable Rarefied Hypersonic, and the wind tunnel is recorded under this name in the European portal MERIL.
The facility was completed in 1963 and is one of the three facilities belonging to the FAST platform and used in the aim of supporting aeronautics and aerospace research.

History

In 1962, the CNES decided to build a low density and high-speed wind tunnel essential for aerodynamic and aerothermal studies in rarefied gas flows. This wind tunnel called SR3 was located in the Aerothermodynamics Laboratory from the CNRS in Meudon. The construction of the facility was delegated to the SESSIA and was achieved in 1963.
The wind tunnel was then moved to the ICARE Laboratory in Orléans in 2000, as a result of the merging of the Aerothermodynamics Laboratory and the LCSR. Then, it was renamed MARHy which is the acronym for Mach Adaptable Rarefied Hypersonic.

Technical details

MARHy is a unique facility in Europe delivering low pressure, super/hypersonic flow in a continuous mode. It is an open-jet wind tunnel.
Dimensions: The wind tunnel is composed of 3 parts:
  • a settling chamber: length of 2.6 m, internal diameter of 1.2 m. It is equipped with a flow breaking cone.
  • a cylindrical test chamber: length of 3.5 m, diameter of 2 m.
  • a diffusor going to the pumping room: length of 10m and diameter of 1.4 m.
Regarding the flow conditions and the rarefaction level, two types of pumping groups are available. 19 different types of flows can be generated, requiring specific generating conditions and thus, relying on variable vacuum pressures. Indeed, for high densities flows, 14 Roots blowers are associated to 2 rotary vacuum pumps.
A wide range of nozzles with various exits shapes going from cylindrical to a truncated cone with an interchangeable col allows an operating domain from subsonic to hypersonic. When a diffusor is added in the extension of the test chamber, a static pressure below 1 micrometer of mercury can be reached.
Mach number MReynolds number Re/cmStatic Pressure P1 Static Temperature T1
0.63.7x10127280
0.85.3x10127266
26x1046.1x103163
22.7x1012.7163
28x1018163
41.8x1022.770
45.7x102870
45x10371.170
6.83.55x1025.0297
121.19x1031.3827
14.94.58x1033.1722
15.11.10x1030.7221
15.34.24x1020.2621
1611.17x1020.5820
16.559x1023.1520
18.47.52x1032.9818
208.38x1020.2114
20.22.85x1020.0713
21.16.68x1031.7314

Tunnel instrumentation

Various types of diagnostics are associated to the wind tunnel MARHy: Pitot Probes, Pressure sensors for parietal measurements, Heat transfer gauges, Infrared thermography camera, iCCD camera & luminescence technique, Aerodynamic balance, Electrostatic probes, Optical spectrometry, Electron gun. They are employed for fundamental and applied studies in the fields of Compressible Aerodynamics, Aerothermodynamics, Atmospheric entries and Gas and Plasma Physics.

Research Applications

The wind tunnel MARHy is extensively used for fundamental and applied research of fluid dynamic phenomena in rarefied hypersonic and supersonic flows.