The Efficiency of High-Speed Wind Tunnels of the Induction Type With an Appendix the Efficiency of Intermittent Operation from Compressed Air Storage

摘要

An investigation has been made of the influence of various design features upon the efficiency of an induction-type tunnel with an annular injector slot. A model tunnel of circular cross-section was used, the working-section diameter being 2J in. At subsonic working-section speeds it was found that efficiencies comparable with those of direct-action tunnels could be attained, but at supersonic speeds the efficiency began to fall rapidly.nThe 12-in., Circular Tunnel (1935) was found to have energy ratios (ratio of the rate of flow of kinetic energy in the working-section to the power required to compress the inducing air isothermally) of 1-7 and 1 - 5 at Mach numbers 0-9 and 1-4 respectively;the present results show that by suitable design these figures can be increased to 5-0 and 2-5 respectively.