Accession Number : ADA186157

Title :   Characterizing Particle Combustion in a Rijke Burner.

Descriptive Note : Interim rept. Feb 86-May 87,

Corporate Author : BRIGHAM YOUNG UNIV PROVO UTAH DEPT OF CHEMICAL ENGINEERING

Personal Author(s) : Finlinson, J C ; Nelson, R W ; Nelson, M A ; Beckstead, M W

PDF Url : ADA186157

Report Date : 29 May 1987

Pagination or Media Count : 24

Abstract : The principle objective of this study is to identify and develop an understanding of the mechanisms whereby acoustic suppressants modify an acoustic wave. The experimental bases for the technical approach of this study is a Rijke burner which generates combustion oscillations. During the past year three major modifications were made to the Rijke burner to facilitate obtaining more reproducible data: (1) The cooling jacket was rebuilt to give better heat transfer characteristics, and a flowmeter was incorporated to allow a quantitative control of the cooling water flow. (2) A digital data acquisition system was interfaced with the burner to allow monitoring more variables, and to improve data reduction techniques. (3) A new damping device consisting of a butterfly valve and a sound absorbing cone below the burner was developed to allow greater damping. Acoustic growth rate data have been obtained a nominal frequency of 1200 Hz varying the mass flow rate, the oxidizer/fuel ratio, and the relative amount of nitrogen. In all cases, the growth rate increases as the energy release rate (or temperature) increases. These data will now be compared to the previously developed model to better understand the physical mechanisms driving the acoustic oscillations. The model is also being modified to incorporate various submodels for different types of particulates. Keywords: Unstable combustion, Acoustic instability.

Descriptors :   *ACOUSTIC DATA, *ACOUSTICS, *HEAT TRANSFER, *OSCILLATION, ACOUSTIC ABSORPTION, ACOUSTIC WAVES, BURNERS, BUTTERFLY VALVES, COMBUSTION, CONICAL BODIES, COOLING, DAMPING, DATA BASES, DATA REDUCTION, DIGITAL SYSTEMS, ENERGY TRANSFER, FLOW RATE, FUELS, GROWTH(GENERAL), JACKETS, MASS FLOW, METHODOLOGY, NITROGEN, OXIDIZERS, PARTICLES

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE