A comparison of two models for predicting the movements of airborne particles from cleaning operations

Measurements of airborne particle concentrations and settle plate counts resulting from the use of a boot scrubber are presented and compared with predictions from two models; one from [Gosman, A. D., Ioannides, E. (1981). Aspects of computer simulation of liquid fuelled combustors. American Institute of Aeronautics and Astronautics 19th aerospace science meeting, St. Louis, MO, 12-15 January, 1981, AIAA paper no. 81-0323; Journal of Energy (ISSN 0146-0412), 7, 482-490] and the other from [Reynolds, A. M. (1998). Modelling particle dispersion within a ventilated airspace. Fluid Dynamics Research, 22, 139-152.]. Both models predicted very high counts within 2 m of the scrubber with much lower counts elsewhere within the room. These patterns were in agreement with measurements. Both models also predicted the positions of highest microbial counts in a room where the scrubber had been operated but they both over-predicted the actual counts probably because not all of the organisms put into the scrubber became airborne. Measured clearance times of the airborne particles were around 50-60 min. Reynolds' model predicted such values whereas Gosman and Ioannides' model predicted times below 12 min and consequently Reynolds' model is preferred.