In order to investigate the flow characteristics of swirl injectors for gelled propellants

which actually behaved as non-Newtonian power-law fluid

a swirl axisymmetric model was established to solve Navier-Stokes equations and VOF (volume of fluid) equation

and the power-law constitutive equation was used to describe the rheology characteristics of the gelled propellants. The film thickness and velocity distribution in the swirl injector under different flow conditions were studied numerically. The simulation results show that the increased geometry characteristic parameter of the swirl injector contributes to the decrease of liquid film thickness. The liquid film thickness is almost independent of the pressure drop. The rheologic parameters have great influences on the inner flow of swirl injector: by increasing the fluid consistency index K and power index n

both the axial and the swirl velocities decrease dramatically; higher fluid consistency index K and power index n make the liquid film thickness increase. When the viscosity is large enough

the air core in the injector would vanish.