Water Spraying from the Roof of a Greenhouse

Water Spraying from the Roof of the Greenhouse, ANSYS Fluent

Description

This project simulates a greenhouse roof watering system — water sprayed from roof-mounted nozzles falling through air and accumulating on the surface below. It offers a clean introduction to two-phase flow under gravity, where the goal is to track where the water goes and how it distributes once it leaves the nozzle.

The case is built as a 2D transient model in Design Modeler, with the domain split into two sections: a resident pool of water at the bottom and an upper region carrying a velocity inlet and an outlet. The tank sides are treated as walls. The domain was meshed in ANSYS Meshing, totaling approximately 208,921 elements.

Methodology

Physics is handled with the Eulerian multiphase model, using air as the primary phase and water as the secondary phase. Water enters at 0.3 m/s, with gravity acting at -9.81 m/s² along the y-axis, and turbulence is closed with the SST k-omega model. Since the spray develops over time — water pumping out, falling, and pooling — the case was solved as transient.

Conclusion

Results include velocity fields and air/water volume-fraction contours that capture the full sequence: water pumping through the roof nozzles, dropping under gravity, and spreading across the bottom surface. The volume-fraction field is the key output, showing coverage and where water collects — exactly what would be tuned in a real irrigation layout to ensure effective, even distribution across the greenhouse floor.