Accession Number : AD0757227

Title :   Droplet Combustion at High Pressures with Unsteady Effects.

Descriptive Note : Final rept. 1 Jun 69-31 May 72,

Corporate Author : INSTITUTO NACIONAL DE TECNICA AEROESPACIAL MADRID (SPAIN)

Personal Author(s) : Tarifa,Carlos Sanchez ; Crespo,Antonio

Report Date : 20 DEC 1972

Pagination or Media Count : 80

Abstract : To describe subcritical combustion, there are quasisteady theories based on the fact that the ratio of gas density to liquid density, epsilon, is small. At large pressures below critical, epsilon is not too small and unsteady effects become more important. It is found that, far from the droplet, at distances of the order of the droplet radius divided by the square root of epsilon, there is a unsteady region that originates corrections to mass burning rates, given by quasisteady theories, of order square root of epsilon. For most hydrocarbons burning in air the flame is located far from the droplet, and its position is not given, even in first approximation, by quasisteady theories. Unsteady effects are also analyzed for forced convection burning with Peclet numbers of order square root of epsilon. (Author Modified Abstract)

Descriptors :   (*FUEL SPRAYS, COMBUSTION), COMBUSTION CHAMBERS, DROPS, BURNING RATE, COMBUSTION PRODUCTS, VAPORIZATION, FLAMES, APPROXIMATION(MATHEMATICS)

Subject Categories : Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE