Intermittent High Reynolds number wind tunnel AIAA-78-766

The paper suggests a simple method o f13; generating intermittent reservoir conditions for an13; intennittent, cryogenic wind tunnel.13; done by operating some existing types o f short-13; duration tunnels ' i n reverse'. Two examples are13; considered (a) a modification of the Ludwieg13; Tube ( b ) the Isentropic Light Piston Tunnel.13; The sizes o f tunnels required to meet the13; European and American specifications for a high13; Reynolds number tunnel with a 10 second running13; time are given together with proposals for a more13; modest National or University facility with a one13; second test time.13; This can be the manufacture o f detailed models the size13; suggested has been increased to 1.9% x 1.65m and13; the tunnel pressure dropped to 4.4 bars.13; influence o f size on cost is so great that the13; cryogenic principle is the least expensive, even13; when applied to a fully continuous tunnel as the13; design submitted implied. Coupled with the unique13; ability to vary Mach nunber, Rey:iolds number and13; the dynamic pressure totally independently, the13; merits of the cryogenic tunnel become irresistible13; Europea countries should at some time and place13; build a continuous cryogenic tunnel.13; worthy tnat the USA i s currently building such a13; tunnel to meet the even more demanding13; specification o f = 120 x 106, = 0.9,13; p = 8.8 bar, with a test section of 8 f t . ( 2 . h )13; sfluare. The decision has now been taken that the It is note