Online Seminar on Aerodynamic interactions in supersonic and hypersonic rarefied flows

Abstract

When a spacecraft re-enters Earth's atmosphere, or in the case of a destructive space debris re-entry, the problem of proximal bodies should be considered. In particular, shock/shock  interferences (SSI) can occur and affect the structure of the spacecraft or the debris trajectory. Depending on the altitude, the objects velocity is hypersonic and they evolve in a rarefied environment, leading to predominant viscous effects. In order to better understand the impact of rarefaction level on SSI, an experimental study was conducted in the MARHy wind tunnel (ICARE, CNRS, France). SSI were obtained with the interaction of two spheres in supersonic and hypersonic low-density flows. Different relative positions were explored to identify various types of interferences occurring in these flows, characteristic of altitudes between 69 and 93 km. Results focus on the visualisation of the SSI, drag and lift forces, and wall pressures measurements. The analysis revealed an important contribution of the viscous effects on the impact of SSI and thus on the aerodynamics of the following sphere.

In the hypersonic case, for which the viscous effects are even greater due to a combination of hypervelocity and low density, the observation of SSI did not allow the identification of clear interference structures. It will be more appropriate to talk about shock/shock mixing layer with strong aerodynamic effects.

Notice: This event is open to public in respect with the VKI eligibility criteria.