Combined near and far field modelling of buoyant plumes

Techniques for the numerical modelling of both the near field of a buoyant plume and the far field (long term build up) are available and are frequently used. In this report buoyancy is generally supposed to be due to temperature differences but the results are also applicable to other kinds of buoyant plume. In engineering applications it is usually the total field that is of interest. The results of the two model studies can be added together to give the total field only by an artificial technique to ensure that no effluent is counted twice. The present report describes how the whole field may be modelled in such a way that the component fields may be added together correctly to yield the total field.