Misting System: Outdoor Ventilation of a Coffeeshop

Misting System for Outdoor Ventilation of a Coffee Shop, CFD Simulation Training

Description

This project simulates a misting system for outdoor ventilation at a coffee shop, modeling a café with two tables positioned under a canopy, with ambient wind blowing at 1 m/s and 305 K. Since the fogging system operates intermittently rather than continuously, a control-based injection approach was used within this transient simulation, specifically investigating the effect of a 0.5-second injection process using the Air/Blast Atomizer model.

The 3D geometry was built in Design Modeler, and the domain was meshed in ANSYS Meshing — first generating an unstructured grid, then converting it to polyhedral cells, totaling 2,358,491 elements.

Methodology

The energy equation was enabled to capture temperature throughout the domain, with turbulence modeled using the Realizable k-epsilon model. The misting system itself was simulated using a combination of the Species Transport model and the Discrete Phase Model (DPM), capturing both the evaporating water vapor and the tracked mist droplets.

Conclusion

Injection begins at 0 s and continues for 0.5 seconds, during which droplet evaporation drives a corresponding decrease in average ambient temperature. The injectors are specifically oriented toward the tables, ensuring customers seated there directly benefit from the misting effect and experience noticeably lower temperatures than the surrounding ambient air.

The average temperature on the mid-plane at each table was tracked and plotted, clearly illustrating how effectively the fogging system reduces local temperature at the points where customers are seated — confirming the misting system's practical value for outdoor thermal comfort in this café setting.