Comparison of Computation Fluid Dynamics Simulation against Tracer Data from a Scale Model and Full-Sized Waste Stabilization Pond

The use of computation fluid dynamics (CFD) for waste stabilization pond design is becoming increasingly common but there is a large gap in the literature with regard to validating CFD pond models against experimental flow data. This paper assesses a CFD model against tracer studies undertaken on a full-sized field pond and then on a 1:5 scale model of the same pond operated under controlled conditions in the laboratory. While the CFD tracer simulation had some discrepancies with the field data, comparison to the laboratory model data was excellent. The issue is, therefore, not in the way the model solves the problem, for example, the choice of turbulence model or differencing scheme, but rather with how accurately the physical conditions in the field are defined. Extensive survey of the sludge layer and transient input of changing flow rates, wind velocities, and temperature could allow closer alignment of CFD simulations to field data. However, in the practical application of CFD where a modification such as baffle installation results in a large change, then a simple pragmatic model, while not exact, can still provide valuable design insight.