Effects of the physical properties of fuel on spray characteristics from a gas turbine nozzle

초록

In a gas turbine combustion system, droplet distribution in the combustor directly affects the combustion process. Fuel droplet size and droplet velocity determine the fuel droplet distribution in the combustor. The present study aims to investigate effects of physical properties on spray characteristics using computational fluid dynamics (CFD) analysis. Spray modeling was performed to analyze the spray characteristics for different fuel physical properties. The hollow cone spray of a gas turbine nozzle was modeled using a LISA (Linearized Instability Sheet Atomization)-TAB(Taylor Analogy Breakup) model with commercial CFD code called, ANSYS Fluent 16.2. The model was validated against the experimental results, which were obtained by PDPA (Phase Doppler Particle Analyzer) and spray tomography. Based on this spray model, the effect of fuel physical properties on spray characteristics were determined. In addition, because the spray patterns differed various injection fluids, the spray characteristics of the gas turbine nozzle with various injection fluids were considered from the perspective of fuel physical properties. It was found that higher density, viscosity and surface tension delayed the atomization process and that density and surface tension have a more significant effect on spray atomization, than viscosity in the catastrophic breakup regime.

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