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ZrB 2 – SiC Sharp Leading Edges in High Enthalpy Supersonic Flows
Author(s) -
Monteverde Frédéric,
Savino Raffaele
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2012.05226.x
Subject(s) - materials science , wedge (geometry) , supersonic speed , thermal conductivity , ceramic , heat flux , composite material , thermodynamics , heat transfer , optics , physics
Aero‐thermodynamic tests have been carried out in an arc‐jet supersonic plasma wind tunnel using a very sharp wedge made of ultra‐high temperature ceramic ( UHTC ) in the ZrB 2 –SiC system. The comparison with a lower thermal conductivity ceramic material (Si 3 N 4 –MoSi 2 ) with the same sharp shape, pointed out at the performance advantages of the UHTC material. When subjected to heat fluxes in the order of 7 MW/m 2 , the surface temperature of the UHTC wedge increased up to 2450°C near the leading edge. The present study demonstrated that the high thermally conductive UHTC survived such extreme conditions by re‐distributing heat over colder regions downstream of the sharp tip. As a consequence, radiative equilibrium temperatures in the range 1400°C–1650°C were established over 85% of the exposed surface. On the other hand, the less thermally conductive Si 3 N 4 –MoSi 2 material failed to withstand the same heat flux and underwent partial melting with significant mass loss. The post‐test microstructural observations of the UHTC wedge proved to be a fundamental source of information which was input into a Computational Fluid Dynamics ( CFD ) code and by a thermal simulation software to simulate the experimental tests and correlate the in situ observations of the material evolution during testing.