Fifth Volta Conference, September 30 - October 6, 1935

Rome

Speakers included

• Adolf Busemann who gave the first public revelation of the swept-wing. He showed how swept-wings would have less drag at high speeds. (The concept was classified as top secret by the Germans one year later, and the impression is sometimes given that the Allies were unaware of the concept prior to the end of the Second World War.

• Eastman Jacobs Methods Employed in America for the Experimental Investigation of Aerodynamic Phenomena at High Speeds, presented wind-tunnel tests at high subsonic speeds, and noted extremely large increases in drag beyond certain Mach numbers.

  He derived and present the basic equations for compressible flow assuming no friction and no thermal conduction. Then he described the NACA High-Speed Tunnel, the schlieren system, and the airfoil experiments carried out in the tunnel. Then came the blockbuster. He showed, for the first time in a technical meeting, some of the schlieren pictures taken at Langley. The pictures gave fundamental information in regard to the nature of the flow associated with the compressibility burble.

  With this, it was claimed that the NACA high-speed research program was leading the pack.

• Ludwig Prandtl presented a series of photographs showing shock waves inside nozzles and on various bodies (Prandtl had been working on supersonic aerodynamics since 1907)

• Jakob Ackeret talked about the design of supersonic wind tunnels which he was establishing in Italy, Switzerland and Deutschland.