Atomization Dynamics of Gel Fuels

Gel fuels combine the high energy density of liquids with the handling advantages of solids by incorporating polymeric gelling agents that yield a viscoelastic droplet shell. Atomization dynamics in such systems are governed by the interplay of rheology, surface tension and inertial forces. Under aerodynamic or mechanical excitation, gel droplets undergo deformation, shell rupture and vapour jetting, leading to complex breakup regimes. The viscoelastic gellant shell may fracture in multiple locations or cascade through successive ruptures, modulating droplet size distribution and trajectory. Control of jetting frequency and droplet size is achieved by tuning polymer concentration, nozzle design and operating conditions. Optimised atomization enhances spray homogeneity, accelerates gas–fuel mixing and ultimately improves combustion efficiency and stability in propulsion and power-generation applications.

Research from Nature Portfolio

Recent studies have revealed that combusting gel droplets exhibit oscillatory vapour jetting driven by cyclic bursting of the gellant shell. Variation in polymer loading yields distinct shell strengths: low loading forms a weak, flexible shell that bursts repeatedly at increasing frequencies in the same region, while high loading produces a rigid shell that ruptures unpredictably across the surface. This self-tuning behaviour enables dynamic control of droplet trajectories and local fuel–oxidiser ratios, offering a route to tailor burn rates and spray patterns in gel-spray propulsion systems.

Atomization Dynamics of Gel Fuels publication trend

The graph below shows the total number of articles in atomization dynamics of gel fuels across all publications each year (not limited to Nature Index journals).

Technical terms

Gellant shell: Viscoelastic outer layer formed by polymeric agent around a gel fuel droplet, which influences breakup and bursting dynamics.

Vapour jetting: Rapid ejection of fuel vapour through ruptures in the gellant shell, enhancing convective mixing and combustion.

Atomization: Process by which bulk liquid fuel is broken into droplets or filaments under aerodynamic or mechanical forces.

Sauter mean diameter: Measure of average droplet size that relates droplet surface area to volume, widely used to characterise spray quality.

Non-Newtonian fluid: Fluid whose viscosity changes with shear rate, characteristic of gel fuels due to polymeric networks.

References

1. Oscillatory bursting of gel fuel droplets in a reacting environment. Scientific Reports (2017).
2. Effects of Temperature on the Flow and Heat Transfer in Gel Fuels: A Numerical Study. Energies (2020).
3. Gel Fuels: Preparing, Rheology, Atomization, Combustion. Energies (2022).
4. Atomization of Gel Fuels with Solid Particle Addition Utilizing an Air Atomizing Nozzle. Energies (2018).