Accession Number : AD0646436

Title :   REDUCTION OF DRAG OF A PROJECTILE IN A SUPERSONIC STREAM BY THE COMBUSTION OF HYDROGEN IN THE TURBULENT WAKE,

Corporate Author : JOHNS HOPKINS UNIV SILVER SPRING MD APPLIED PHYSICS LAB

Personal Author(s) : Baker,W. T. ; Davis,T. ; Matthews,S. E.

Report Date : 04 JUN 1951

Pagination or Media Count : 29

Abstract : An experimental evaluation was made of the effect of combustion of hydrogen with the wake air on the drag of a projectile. The base drag was reduced by about two-thirds, and hence total drag of a flight unit may possibly be reduced one-third, by the use of a minimum of 6.4 per cent of the stoichiometric requirement of the air swept by the maximum cross-sectional area. No difficulty was experienced in igniting the hydrogen. From data obtained from Experiment Incorporated it appears that a solid fuel charge might be employed to achieve this drag reduction for a projectile in flight. The use of a pyrotechnic magnesium charge in the form of a cylinder attached to the base of a projectile would require consumption at the rate of 0.17 inch per second at sea level to achieve the same heat release. The burning rate is approximately proportional to pv, tending to maintain combustion temperature during variations of altitude and speed. (Author)

Descriptors :   (*PROJECTILES, DRAG), (*HYDROGEN, COMBUSTION), SUPERSONIC FLOW, REDUCTION, WAKE, TURBULENCE, FLIGHT, AIR

Subject Categories : Fluid Mechanics
      Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE