SILENT

The development of hypersonic vehicles (with a Mach number greater than 5) is strategically vital for advancing aerospace capabilities in the defence and civil sectors. The performance, safety and efficiency of these vehicles depend critically on our ability to understand and control the boundary layer — the thin region of air directly on the vehicle’s surface. The transition of this layer from a smooth (laminar) to a chaotic (turbulent) state dramatically increases heat loads and drag, posing a major risk to any mission. Reliable experimental data is therefore essential for validating designs. However, Europe’s existing hypersonic wind tunnels generate high levels of acoustic noise that are not present in flight, failing to accurately replicate these critical conditions. This creates a significant capability gap and leaves European industry and research reliant on test facilities in other countries.