To explore the effect of yield stress on the secondary breakup of gel drops, experimental and theoretical investigations are carried out by employing a high-speed camera. A unique hemline-type breakup, as a modified behaviour of sheet-thinning breakup, occurs when the air velocity increases to a high region. The edges of the drops constantly deform into thin membranes when the high-velocity air skims over the gel drops. These membranes vibrate vertically, and breaking points occur at high amplitudes, causing the formation of reticular fragments. The results of linear stability analysis indicated that the yield stress of the gel drops has an influence on the formation and breakup of the gel membranes. The breakup regime map and breakup times are also studied.

To explore the effect of shear thickening behavior on the secondary deformation and breakup of cornstarch–water suspension droplets, an experimental investigation is conducted by using a high-speed camera. The experimental results demonstrate suspension droplets that exhibit discontinuous shear thickening (DST) exhibit a hardened deformation mode when they fall into the airflow field. When the droplets are in a hardened deformation mode, the windward side of the droplet deforms into a sheet, while the leeward side remains hemispherical until the droplet leaves the airflow field. The dimensionless number N is established to describe the relative magnitude of the increment of the viscous force and aerodynamic force during the secondary breakup process. Based on the suggested dimensionless number N and the Weber number We, the secondary deformation and breakup regime map of Newtonian fluids and DST suspensions is also proposed.

The addition of aluminum particles to gel propellants can improve combustion performance. However, the agglomeration of aluminum during the combustion process can result in a series of negative effects. In this paper, the aluminum agglomeration inhibition method of gel propellant based on carbon synergistic effect is proposed. Carbon particles exhibit excellent combustion properties, and the gaseous product CO₂ generated during combustion can mitigate the agglomeration of aluminum. The research demonstrates that incorporating carbon particles into aluminum-containing gel effectively reduces the incomplete combustion of aluminum particles and increases the volumetric calorific value of the gel. When the mass fraction of carbon is 5 wt%, the volume calorific value of the gel reaches the highest. Meanwhile, the rheological experiments show that the addition of carbon particles can improve the shear-thinning properties of the gel, which is beneficial to the atomization and combustion processes of the gel.

Coaxial atomization of a gelled jet is affected by yield stress and gas swirl. Linear instability analysis is used to explore the impact of these two factors.