European Transonic Windtunnel

The facility was originally built and operated by France's ONERA, the UK's Department of Trade and Industry (DTI), the Dutch NLR and the DLR. France, the United Kingdom and Germany each held 31 percent, while the Netherlands held 7 percent. ONERA left the consortium in 2012. Today, the DLR owns 45 percent of the company, BIS and QinetiQ together hold 45 percent, and the NLR holds 10 percent.

Pressure, temperature and speed are controlled separately. This allows Mach number, Reynolds number and dynamic pressure to be set independently of one another, so the effects of compressibility, model deformation and scaling can each be examined in isolation. According to the operator, this is based on the cryogenic concept of a pressurized wind tunnel. Only NASA's National Transonic Facility (NTF) at the Langley Research Center in the USA offers comparable capabilities.

Measurements are taken at pressures from 1.15 to 4.5 bar. For full models, the tunnel reaches Reynolds numbers of up to 50 million, and up to 85 million for half models. The models have a wingspan of about 1.5 m; for half models, this refers to the half-span. According to the operator, a modular model cart concept makes it possible to prepare and carry out test campaigns in parallel.

According to the operator, aircraft manufacturers from around the world and European researchers work with the facility. One example is the AWATAR project, in which the DLR and Airbus used the ETW to study a strut-braced wing configuration with a very high aspect ratio. The operator sees the ETW as complementing the DNW-LLF and ONERA-S1MA wind tunnels, and points to its classification as a strategic European wind tunnel by the Advisory Council for Aviation Research and Innovation in Europe (ACARE). To protect customer data, all employees have signed confidentiality agreements, according to the operator.