Artificial Indoor WaterFall

Malls and airports today are sometimes based on different themes, often mimicking a jungle or some natural environment. Waterfalls are an important and aesthetic aspect when mimicing such environments. Although aesthetically pleasing, these indoor waterfalls result in huge load on the HVAC systems due to extensive humidity generation. To counter this problem, it is important to quantify the humidity generated due to the waterfall.

In this project, we simulate a multiphase flow with species transport  to simulate an indoor waterfall and the resulting humidity generation. 

Water falls from a 13m high inlet and exits the domain through the outlet. The domain is maintained at 25 degree celcius and 50% relative humidity (RH). There are multiple ways to calculate humidity generation highlighted in research literature but in this case, we use a simple humidity rate generation method to calculate the humidity where we calculate the difference in humidity generation between two time intervals within the domain.

The simulation settings are as follows :

Turbulence model: k-omega SST

Multiphase model: VOF

Species transport : Air and water-vapor mixture.

Evaporation condensation : Lee model

Solver: PISO

Inlet: 30 kg/s at 291.05K (wet bulb temperature of water at 25 C and 50% RH)

Phase change: 287.25 K (Saturation temperature of water at 25 C and 50% RH)

Outlet: 0 Pa, mixture backflow with 0.99 mass fraction(for 50% RH)

Results