A Eulerian Wall Film CFD simulation is a computer model that studies how a thin liquid layer forms on a surface. This is very important for processes like painting, cooling, and advanced manufacturing. An Eulerian Wall Film Fluent simulation is especially useful for a Moving Spray CFD analysis, where the nozzles move around. This type of Spray Forming Simulation often uses the Discrete Phase Model (DPM) to track individual liquid droplets from the nozzle to the wall. This DPM Spray CFD analysis, combined with a Dynamic Mesh Fluent model for the moving parts, allows engineers to see exactly how the spray creates a coating. It helps predict the final coating thickness and quality, which is critical for making high-quality products. For more DPM and spray CFD simulations, explore our comprehensive collection at CFDLAND DPM Simulations.

Figure 1: A conceptual diagram showing how the Eulerian Wall Film model works in a spray application.

Simulation Process: Fluent Setup, Dynamic Mesh and DPM for a Moving Dual-Head Spray

To perform this Eulerian Spray film CFD study, we used a full transient simulation in ANSYS Fluent. This is necessary to see how the process changes over time. A key part of the setup was the Dynamic Mesh model. This powerful feature allowed us to simulate the real movement of the two spray nozzles as they travel across the surface. This is critical for accurately modeling the coating process. We defined two different spray sources using the Discrete Phase Model (DPM) to represent the dual-head system. One injection released anthracite particles, and the other released water droplets. To make the simulation realistic, we activated 2-Way DPM coupling. We also used unsteady particle tracking, which calculates the path of each droplet at every moment in time, which is essential for a moving system.

The most important model for this study was the Eulerian Wall Film model. We set water as the film material, with a surface tension of 0.07194 N/m. This model calculates how the liquid droplets, once they hit the surface, form a thin film, spread out, and build up. We also activated advanced DPM settings to control how droplets behave on impact, including rules for splashing and separating, to ensure the simulation was as close to reality as possible.

Post-processing: CFD-Post Analysis, Quantifying Film Uniformity from a Dual-Nozzle System

The results not only show the final coating but also explain how it was formed, which is critical for process control. The film thickness contours in Figure 2 show the final result of the coating process. The thickness ranges from nearly zero up to a maximum of 3.52e-05 meters. We can clearly see two distinct deposition tracks, one for each nozzle. The red and orange areas in the center of each track show where the deposition is heaviest, directly under the path of the spray nozzles. The green and yellow areas show where the two spray patterns overlap, creating a more uniform coating between the tracks. The perfectly symmetrical pattern proves that both nozzles are working equally, which is a key requirement for a good dual-head system.

The film coverage contours in Figure 3 support this finding. The red areas show complete surface coverage (a value of 1.0), confirming that the nozzle spacing and spray angle were chosen correctly to avoid any gaps in the coating. The details in Figure 4 give us confidence in these results. They show a very consistent and even film thickness of 2.82e-07 meters within the main deposition channels. This high level of uniformity is a primary goal in any industrial coating process. The animation of the results confirms that the dynamic mesh and unsteady particle tracking worked perfectly, showing the film building up realistically over time as the nozzles move.

Figure 2: Film thickness distribution contours from the Eulerian Wall Film Fluent simulation, showing deposition patterns from the dual-head spray.

Figure 3: Film coverage contours from the Moving Spray CFD analysis, indicating the areas of the surface covered by the liquid film.

The detailed film thickness visualization in the spray deposition channels provides critical insight into wall film formation mechanisms in our Eulerian Wall Film Fluent CFD analysis. The film thickness contours show uniform values of 2.82e-07 m across the wetted surfaces, indicating consistent deposition and stable film formation in the channel regions. The uniform film thickness of 2.82e-07 m in the channels confirms that the Eulerian Wall Film model accurately predicts film establishment and spreading behavior. The 3D visualization clearly shows two parallel deposition tracks corresponding to the dual nozzle configuration, with well-defined boundaries between wetted and dry regions. The film patterns demonstrate effective spray overlap and continuous coverage along the nozzle travel paths, essential for uniform coating in industrial spray forming. The animation results show dynamic spray formation and progressive wall film establishment as the moving nozzles deposit material across the substrate surface. The film development process shows initial droplet impact, film spreading, and thickness buildup over time.

Figure 4: A contour showing the spray formation and the establishment of the wall film, captured by the Unsteady Particle Tracking model.