CFD modelling of livestock odour dispersion over complex terrain, part II: Dispersion modelling

A computational fluid dynamics (CFD) model was developed to predict livestock odour dispersion over complex terrain. The modules for atmospheric dispersion modelling (MADM) were designed to consider physical phenomena such as wind shear, insolation flux from the ground, and atmospheric stability. The modules were connected by user defined functions and schemes to a CFD solver. The model was validated by using the distributions of livestock odour, wind velocities, and wind directions measured in field experiments. The wind field, computed by unsteady and large eddy simulation (LES), agreed well with the measured field wind variations. Odour dispersion was also well predicted, with a correlation coefficient of 0.863. By applying the CFD model to two test areas in Cheongyang and Yesan, Korea, odour distributions were predicted with several variations in atmospheric stability, wind speed, and wind direction. Several possible weather conditions were selected for each area and the results compared with each other. The CFD model and the MADM were very effective for predicting odour dispersion under various weather conditions. The model and the module are expected to facilitate environmental impact evaluations and dispute mediation in matters related to livestock odour.

Research highlights
► MADM (modules for atmospheric dispersion modelling) were developed.
► The MADM created a real-time wind environment linked to the FLUENT main module.
► The CFD model with the MADM was well validated with the results of field experiments and predicted the odour dispersions under various weather conditions.
► CFD model combined with MADM was very effective for predicting odour dispersion from a livestock farm under various weather conditions, even in unsteady weather.