Modelling of particle-wall deposition in two-phase flows

The ultimate aim of this project was to investigate and develop a computational model which can be used in conjunction with a CFD code for URANS (and eventually coarse-grid LES or hybrid RANS-LES methods) to predict the formation of deposit of solid particles on oblique wall surfaces as encountered in biomass-fired boilers and auxil-iary equipment. Specifically, the target is to predict the dynamics of deposit formation (the growth rate and the shape of the deposit) on the furnace interior walls, but also (and even more importantly) on tubes and bounding walls of superheaters, heat exchangers and other equipment in which the boiler flue gases are used or processed. This applica-tion, involving relatively large particles (over 10 microns) immediately imposes some specific constraints, but also eliminates the need to consider phenomena that are specifi-cally related to smaller (submicron and nano-particles). Notwithstanding these specific effects, a practically useful model should still account for a variety of phenomena and issues.