Mario De Stefano Fumo

Thermal Shielding of a Reentry Vehicle by Ultra-High-Tempreature Ceramic Materials

Reentry vehicles with enhanced aerodynamic performances and high maneuverability require sharp leading edges for the wings and control surfaces and a sharp tip of the fuselage nose where high localized heat fluxes occur. Ultra-high-temperature ceramics, for example, zirconium, hafnium, or titanium diborides, are candidate materials for the sharp edges of reentry vehicles that make use of new thermal protection systems, positioning massive thermal protection systems only at the leading edge of the wings (or at the fuselage tip). The boundary-layer thermal protection concept is illustrated, and the requirements for the geometry and materials of the fuselage nose are identified. It is shown how a sharp nose will protect the fuselage, acting as a lightning rod for the rest of the structure when the vehicle flies at relatively low angles of attack. Systematic numerical analyses are shown for the sphere-cone nose vehicle to compute temperature distributions along the surface and inside the nose structure at different angles of attack. The effects of the chemistry and of the surface catalysis are discussed.

Aerothermodynamic Study of Ultrahigh-Temperature Ceramic Winglet for Atmospheric Reentry Test

This paper deals with the aerothermodynamic analysis of an advanced concept of hot structure to be investigated at atmospheric reentry conditions. The paper gives a general description of the hot structure architecture and performs an aerothermodynamic analysis to optimize the winglet configuration, based on an ultrahigh-temperature ceramics leading edge able to withstand very high temperatures. Three-dimensional fluid-dynamic computations are carried out to evaluate the aerothermal loads on the winglet. The physical model includes viscous effects, real gas properties, nonequilibrium chemical reactions and surface catalytic effects. The numerical model has been validated by experimental results of two- and three-dimensional hypersonic flowfields. A thermal model of the structure has been implemented to predict the temperature of the winglet during reentry. The results are discussed with reference to the effects of the thermal interaction with the capsule skin, the relevance of thermal conduction inside the structure, and the transient methodology. The effect of different assumptions on the ultrahigh-temperature ceramics catalytic properties is discussed.

Thermal shielding of a re-entry vehicle by UHTC materials

Re-entry vehicles with enhanced aerodynamic performances and high maneuverability require sharp leading edges for the wings, control surfaces and sharp tip of the fuselage nose where high localized heat fluxes occur. Ultra High Temperature Ceramics (UHTC) , e.g. Zirconium, Hafnium or Titanium Diborides, are candidate materials for the sharp edges of reentry vehicles that make use of new Thermal Protection Systems, positioning massive TPS only at the leading edge of the wings (or at the fuselage tip). The Boundary Layer Thermal Protection concept is illustrated in this paper and the requirements for the geometry and materials of the fuselage nose are identified. It is shown how a sharp nose will protect the fuselage acting as a “lightning rod” for the rest of the structure when the vehicle flies at relatively low angles of attack. This paper shows systematic numerical analyses for the spherecone nose vehicle to compute temperature distributions along the surface and inside the nose structure at different angles of attack. The effects of the chemistry and of the surface catalysis are discussed.

PHOEBUS: GNC Design and Performance Assessment for super orbital Re-Entry

PHOEBUS (Plane-shaped Hypersonic Orbital Re-Entry BUS) is a manned spaceplane vehicle concept under definition in the frame of an European Space Agency (ESA) contract. This paper focuses on the Guidance Navigation and Control (GNC) design proposed for a super orbital entry applied to this high Lift-to-Drag ratio (L/D) vehicle. GNC system design is driven by the innovative entry strategies that, by exploiting the vehicle’s high L/D capabilities, allow a smooth re-entry (1-2 g decelerations) and high flexibility in manoeuvering from Entry Interface (EI) to Terminal Area Energy Management (TAEM).