AIRCRAFT RESEARCH

Hokitika Guardian, 15 November 1930, Page 7

AIRCRAFT RESEARCH

REDUCTION OF NOISE. LONDON, 'October 2. The Aeroplane Research Committee, in its report for 1929-30, issued this week, draws attention to the steady expansion of activities in aeronautics throughout the world, and to the consequent increase in the number of problems awaiting solution which have been brought to its attention in connection with development within the British Empire. One of the problems considered by the committee was that of spinning, which the Air Member for Supply n.nd Research has stated to be “one of the most practical problems yet to be solved.” The committee had recommended that certain researches bearing upon this matter should take first priority.

Among other problems were the development of compression ignition engines, in which the fuel-air mixture in the cylinder is ignited by. the act of compression, and an inquiry on the values for aircraft purposes of single sleeve-valve engines.

Three initial steps have been taken in the attempts made to analyse and reduce noise in aircraft. A table instrument had been constructed for measurement and analysing sounds, the chief sources of sound were being separately investigated, and measurements had been made of the extent to which various materials, when used to line the walls, excluded noise from the cabins. A preliminary measurement already made of the noise within the cabin shows that it is about one thousandfold greater in energy intensify than that experienced in an express train, and the committee hopes within a short period to reduce this a mount of noise appreciably.