MARHy Wind Tunnel
The MARHy Hypersonic low density Wind Tunnel, located at the ICARE[1] 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 under the european portal MERIL.[2] The facility was completed in 1963 and is one of the three facilities belonging to the FAST platform (composed of two other wind tunnels) and used in the aim of supporting aeronautics and aerospace research.
History
In 1962, the CNES (France’s National Centre for Space Studies) 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[3] was located in the Aerothermodynamics Laboratory from the CNRS (France's national scientific research center) in Meudon. The construction of the facility was delegated to the SESSIA (engineering consultants for aeronautical industrial works) 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 (Combustion and Reactive Systems Laboratory). 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 M | Reynolds number Re/cm | Static Pressure P1 (Pa) | Static Temperature T1 (K) |
|---|---|---|---|
| 0.6 | 3.7x101 | 27 | 280 |
| 0.8 | 5.3x101 | 27 | 266 |
| 2 | 6x104 | 6.1x103 | 163 |
| 2 | 2.7x101 | 2.7 | 163 |
| 2 | 8x101 | 8 | 163 |
| 4 | 1.8x102 | 2.7 | 70 |
| 4 | 5.7x102 | 8 | 70 |
| 4 | 5x103 | 71.1 | 70 |
| 6.8 | 3.55x102 | 5.02 | 97 |
| 12 | 1.19x103 | 1.38 | 27 |
| 14.9 | 4.58x103 | 3.17 | 22 |
| 15.1 | 1.10x103 | 0.72 | 21 |
| 15.3 | 4.24x102 | 0.26 | 21 |
| 16 | 11.17x102 | 0.58 | 20 |
| 16.5 | 59x102 | 3.15 | 20 |
| 18.4 | 7.52x103 | 2.98 | 18 |
| 20 | 8.38x102 | 0.21 | 14 |
| 20.2 | 2.85x102 | 0.07 | 13 |
| 21.1 | 6.68x103 | 1.73 | 14 |
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 (near IR, visible and VUV), Electron gun (not available). They are employed for fundamental and applied studies in the fields of Compressible Aerodynamics, Aerothermodynamics, Atmospheric entries and Gas and Plasma Physics.
Purpose and use
The wind tunnel MARHy is extensively used for fundamental and applied research of fluid dynamic phenomena in rarefied compressible flows. Some works undertaken with this facility are listed here:
- study of compressible flows around models
- structure of wakes in supersonic rarefied flows
- double injection nozzle
- atmospheric entries
- plasma actuators[4]
s[5]
Gallery
Photo of the experiment with an electron gun.
iCCD image of an Hermès model in a Mach 20 flow.
Photo of the glow discharge with a plasma actuator.
References
- ↑ ICARE Laboratory, CNRS, Orléans
- ↑ MERIL, the european facilities platform
- ↑ Jean, Allègre (1992). "The SR3 low density wind tunnel. Facility capabilities and research development". 28th Joint Propulsion Conference and Exhibit.
- ↑ Sandra Coumar, Viviana Lago (2016). "Influence of a plasma actuator on aerodynamic forces over a flat plate interacting with a rarefied Mach 2 flow". 26 (7). International Journal of Numerical Methods for Heat & Fluid Flow. pp. 2081–2100..
- ↑ Viviana Lago, Romain Joussot (2014). "Influence of ionization rate of a plasma discharge applied to the modification of a supersonic low Reynolds number flow field around a cylinder". 47 (12). Journal of Physics D: Applied Phys. p. 125202..