AEROSPACE
METASTARS
Advanced re-entry systems: OCMC inlet design
for an inflatable atmospheric decelerator
OUR ROLE
Aerothermodynamic design of the inlet
MATERIALS
Oxide Ceramic Matrix Composites (OCMC)
PRESENTED AT
International Astronautical Congress, IAC 2024
01
OBJECTIVE
Reusable atmospheric re-entry brings a frontier problem with it: an air intake that has to work at hypersonic speed, up to Mach 27, at temperatures approaching 1000 K, integrated into an Inflatable Atmospheric Decelerator.
The concept behind it is worth stating plainly, because it is what makes the difficulty worth accepting: inflate the decelerator with atmospheric air taken in during re-entry rather than from pressurised tanks. No tanks means less mass, better efficiency, and a system that can be flown again.
02
OUR CONTRIBUTION
NablaWave led the aerothermodynamic design of the inlet, building CFD models for chemically non-equilibrium hypersonic flow — multi-species, finite-rate chemistry — across both the hypersonic and transonic regimes.
The models were validated against experimental benchmarks, among them bow shock stand-off distance, and then used to optimise the inlet and duct for flow uniformity and pressure recovery, and to study how the external flow interacts with the internal compression system.
Making it was a second problem. OCMC was chosen for its tolerance of extreme thermal load and shock, which meant the design had to satisfy aerothermodynamics, fibre orientation and manufacturable geometry, and a multi-part manufacturing process, all at once. The prototype was then tested in a plasma wind tunnel under representative re-entry conditions, which found the localised critical areas under extreme heat flux and fed them back into the design.
03
OUTCOMES
The key numerical result was a negative one, and the most useful kind: drawing air in for inflation does not significantly disturb the bow shock. The concept survives its own physics.
Across the numerical and experimental campaign: stable aerodynamic behaviour under extreme hypersonic conditions, flow uniformity at the compressor interface improved to a coefficient of variation of about 0.55, and OCMC structures that kept their integrity despite localised damage.
04
WHAT IT OPENS
This is among the first studies to integrate aerothermodynamics with an air-breathing compression system during atmospheric re-entry, and it leaves clear routes for further optimisation in geometry, materials and thermal protection.
For us it is evidence of something harder to state in a datasheet: CFD for hypersonic flow with non-equilibrium chemistry, geometry optimised under tightly coupled multi-physics constraints, and a design taken all the way to a tested article.