An approximate analytical model for the frequency response of evaporating droplets under a mixed feeding regime

Abstract

This work is one of the analytical approaches to evaluate the evaporation frequency response of injected droplets, using the Heidmann analogy of a single droplet that is continuously fed with the same liquid fuel. Based on a linear analysis using the Rayleigh criterion, a dimensionless response factor is determined. The effects due to the variation of the heat transfer coefficient of the feeding process, as well as those due to the characteristic evaporation times and phase delay are analyzed. An abrupt increase of the response factor occurs, when a thermodynamic coefficient of the injected fuel takes certain specific values.

Keywords

• Combustion instability
• Injection regime
• Evaporation
• Double confluent Heun equation
• Transfer function