Chemical: Spray using Injection in DPM

This project simulates a water spray issuing from a small circular inlet into a larger cubic enclosure, tracking the behavior of the spray particle by particle. It's the standard introduction to the Discrete Phase Model (DPM) — the Lagrangian approach Fluent uses when you care about the trajectory, velocity, and dispersion of individual droplets rather than a continuous second phase.

The geometry is a rectangular cube with a circular inlet on the top wall, built in Design Modeler and meshed in ANSYS Meshing with an unstructured mesh (25,464 cells). Because droplets move discretely through a continuous medium, the case is solved with a Lagrangian DPM layered on the continuous (Eulerian) air flow, and run transient to capture how the spray develops in time.

The key setup step is defining the injection: water is released as a surface injection from the inlet, with the droplets treated as inert particles. This is where DPM differs from a multiphase model — you specify how, where, and at what size/velocity the particles enter, and Fluent integrates each trajectory through the flow field.

What the results show: velocity and mass-concentration contours of the water particles at the final time step, plus 3-D particle tracks colored by particle speed and droplet diameter. The tracks confirm the injection is set up correctly — droplets disperse discretely from the top inlet and distribute through the enclosure, which is exactly the behavior you'd analyze when sizing nozzles or predicting coverage.

You'll learn to: distinguish DPM (Lagrangian) from Eulerian multiphase, define a surface injection of inert particles, couple the discrete phase to a transient continuous flow, and read spray behavior from particle tracks and concentration contours.