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|Title:||An Experimental Investigation of Two-Dimensional Flame-Vortex Interactions (Acoustics Addition Rate)|
|Author(s):||Yip, Tsun-Wai Gary|
|Department / Program:||Aeronautical and Astronautical Engineering|
|Discipline:||Aeronautical and Astronautical Engineering|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Experiments have been performed to study the interaction between a flame and a single vortex impulsively generated by the flame. The objectives are to investigate the amplitude of the cylindrically diverging acoustic wave produced by the interaction and to develop a quantitative approach to determine the degree of violence of the flame-vortex interaction. With the Reynolds number, defined as the ratio of the strength of the vortex to the kinematic viscosity of the unburned gas, characterizing the unburned gas flow condition quantitatively, the acoustic pressure (TRIANGLE)p(t) generated by the interaction has been measured at distances 1.5, 1.75 and 2.0 meters away from the interaction zone using a microcomputer-based data acquisition system and a storage oscilloscope. The dimensionless time rate of change in the heat addition rate, Q(t), of the flame-vortex interaction, is deduced from the acoustic pressure data via the line source equation in linear acoustic theory. The Fast Fourier Transform has been used to perform the analysis.
For the thirty experiments performed, the amplitudes of Q(t) and (TRIANGLE)p(t) have been found to be dependent on Re, the burning speed of the mixtures as well as two dimensionless geometric parameters. The results show that Q(,max) increases with Re and the burning speed, when the geometric parameters are fixed. An empirical logarithmic equation has been obtained to describe the variation of Q(,max) for Re between 10('5) and 4.5 x 10('5). The maximum (TRIANGLE)p(,max) recorded was 72 mbar at 1.5 m from the interaction zone. The increase in the "violence" of the interaction has been found to be associated with an increase in the heat addition rate during the period of flame-vortex interaction.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1984.
|Date Available in IDEALS:||2014-12-15|