Date of Completion

10-22-2014

Embargo Period

10-21-2014

Advisors

Michael W. Renfro, Tianfeng Lu

Field of Study

Mechanical Engineering

Degree

Master of Science

Open Access

Campus Access

Abstract

Flow field characteristics of multiple reacting jets in vitiated crossflow are investigated. The effects of changing jet geometry and momentum flux ratio on the jet trajectory and mixing were studied experimentally and numerically. Through measurement of velocity field of jets utilizing particle image velocimetry (PIV), differences in the experimental jet penetration were found for the configurations tested. An increase in momentum flux ratio increased jet penetration, ranging from 11% to 22% increased penetration. A similar effect on penetration was also seen when the jet geometry was changed. PIV measurements also indicated that the reacting jets penetrated less than the non-reacting cases, showing a decrease in penetration ranging from 10 to 16% measured at downstream locations x/D=1 and x/D=2. This observation was possibly due to increased confinement and blockage effects from gas expansion, reducing penetration.

Jet fluid mixing was also analyzed utilizing numerical simulations. It was found that the higher momentum flux ratio lead to better mixing than the lower momentum flux ratio. Furthermore, it was seen that the computational mixing study performed for the non-reacting jets was reasonable in predicting the consumption of fuel in the reacting case, and could potentially be used to predict combustion efficiency.

The results from the experiment and the simulations were compared with each other. It was found that the numerical results for the non-reacting trajectory over-predicted the experimental jet trajectory for the L/D=2.1, J=16.7 case. Moreover, the computations predicted that the reacting jets penetrated farther into the crossflow than the non-reacting jets, contrary to what was observed in the experiments.

Major Advisor

Baki M. Cetegen

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