Unstable breakup of a power-law liquid fuel jet in the presence of a gas crossflow

Abstract

A theoretical model is presented for the effect of a slight gas crossflow on the instability of the power-law fuel jet in this paper. Based on a linear approximation, the dispersion equation was deduced theoretically with axisymmetric disturbance. The influence of various dimensionless factors for jet instability is studied. Theoretical calculation results of temporal mode show that the transverse motion of gas phase could effectively accelerate the power-law fuel breakup. With the increase of transverse gaseous velocity, power-law fuel jets would become more susceptible to be broken up. Increasing gas-liquid density ratio could enhance the aerodynamic forces in the axial and vertical directions and promote fuel fragmentation. Simultaneously, a huge gas density could weaken the influence of transverse airflow. With the increase of the transvers airflow, Weber number has a weakening effect on the fuel breakup, but it has a significant positive effect on the primary breakup scale. However, with gas crossflow, the liquid viscous force also takes strong disadvantage of development of surface wave. Besides, the effects of crossflow and co-current airflow environments on the instability of power-law liquid jet are studied. For the generalized Reynolds number and power law exponent, the fuel jet under cross-flow conditions is more unstable, but the jet under the co-current flow condition is smaller on the fracture scale. These issues are beneficial to understand the disintegration of the power-law fuel jet with gas crossflow, and supply reference for the application of power-law liquids in real engineering technologies.