Diesel Spray Atomization Modeling Techniques

Diesel spray atomization modelling lies at the heart of modern engine design, aiming to predict how liquid fuel disintegrates into droplets and mixes with air. Key challenges arise from the wide range of spatial and temporal scales: in-nozzle flow may occur over micrometres and microseconds, whereas spray breakup and dispersion extend to millimetres and milliseconds. Approaches fall broadly into Lagrangian frameworks, which track discrete droplet parcels, and Eulerian multi-fluid formulations, which treat droplet size classes as interpenetrating continua. Primary breakup models describe the initial disintegration of the liquid core into ligaments or large droplets, often driven by aerodynamic instabilities, while secondary breakup models govern the further fragmentation of those primary structures. Numerical solvers incorporate turbulence closures, interfacial momentum transfer, evaporation and thermal effects to reproduce spray geometry, droplet size distributions and evaporation rates. Advances in high-performance computing now enable fully three-dimensional simulations that couple detailed in-nozzle flowfields to downstream spray dynamics, offering insight into rate-of-injection transients, spray cone angles and Sauter Mean Diameter distributions. Such predictive capability supports optimisation of injector design, combustion efficiency and emissions reduction across a broad spectrum of operating conditions.

Research from Nature Portfolio

Recent studies have introduced an end-to-end modelling framework that decouples in-nozzle flow and spray atomization via a static coupling strategy. High-fidelity computational fluid dynamics (CFD) simulations sample the flowfield at the injector exit, generating time-resolved maps that initialise a Lagrangian spray solver. This approach captures fine-scale flow structures and their influence on initial ligament formation, enabling accurate predictions of injection rate profiles and downstream spray morphology. Validation against optical diagnostics confirms that static coupling uncovers spray features previously unresolved in conventional one-way coupled models.

Diesel Spray Atomization Modeling Techniques publication trend

The graph below shows the total number of articles in diesel spray atomization modeling techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Static coupling framework: A strategy that decouples in-nozzle CFD simulations from downstream spray models by exchanging flowfield data at the injector exit.

Eulerian multi-fluid model: A continuum approach that represents droplets of different size classes as interpenetrating phases, each with its own set of transport equations.

Lagrangian approach: A particle-based method that tracks discrete parcels representing clusters of droplets through the flowfield.

Primary breakup: The initial disintegration of the liquid jet or core into ligaments and large droplets, driven by aerodynamic instabilities.

Sauter Mean Diameter (SMD): A metric for characterising droplet size distribution, defined as the diameter of a sphere with the same volume/surface-area ratio as the spray.

References

1. End-to-end modeling of fuel injection via static coupling of internal flow and ensuing spray. Communications Engineering (2022).
2. Development of a Eulerian Multi-Fluid Solver for Dense Spray Applications in OpenFOAM. Energies (2020).
3. A Eulerian Multi-Fluid Model for High-Speed Evaporating Sprays. Processes (2021).
4. Investigation on Primary Breakup of High-Pressure Diesel Spray Atomization by Method of Automatic Identifying Droplet Feature Based on Eulerian–Lagrangian Model. Energies (2022).