Models for the ETW and NTF high Reynolds number cryogenic wind tunnels have to be manufactured from exotic high tensile steel to withstand the loads generated at cryogenic test conditions and also require a surface finish much better than models for the ARA tunnel (Ra = 0.1 to 0.2 µm). ARA has been at the forefront of material, tool and technique development and model design and manufacture of cryogenic models.
In 1989 ARA participated in a 5 year technology programme to investigate design and manufacture issues (e.g. steels, fasteners, tools, bonding and seal materials). In 1994 ARA designed and manufactured the ETW reference model with no external fasteners and support sting and then continued to design and manufacture the ETW half model balance, turntable and thermal controls. In 2004 we were able to design and manufacture a complex, high-lift semi-span model for the ETW and NTF.