PhD Thesis - staffweb - University of Greenwich

PhD Thesis by John Ewer.6 Research results6.1 OverviewIn order to investigate the potential effectiveness of user interaction techniques, forComputational Fluid Dynamics (CFD) modelling, it was decided to choose an application areathat gave ready access to a number of CFD experts and furthermore was an application areawhere the accuracy and correct interpretation of results was of a safety critical nature. One suchtopic of research at the University of Greenwich is Fire Field modelling. This application areais interesting because of the complexity of the geometry used in the simulations and therequirements for the modelling of high rates of heating and thermal radiation [KUMAR91].Furthermore, many fire simulations have to be performed in transient mode so that the timevarying nature of the simulation is revealed. This is partly due to the extremity of the physicsbeing modelled but also due to the types of question asked of the modelling which includes thedetermination of temperatures and smoke concentrations at certain times in order to researchsafety issues relating to, for example, fires in compartments and buildings [LEWIS97]. Theadded advantage of using this application area is that there is considerable “in-house” expertiseavailable for the use of fire field modelling. Of particular importance have been the comparisons[KERRISON94] [BJORKMAN95] of various CFD codes against the experimental work ofSteckler [STECKLER82] which give a useful set of validation and comparison data for themodelling of fires within compartments.The results presented in this section are indicative rather than exhaustive but the intention hasbeen to demonstrate that the traditional techniques used for CFD in general and Fire Modellingin particular have mostly ignored the issues of interactive solution control, to their detriment.Recent questions about the reliability and accuracy of CFD techniques used in ever more criticalsimulations will, almost inevitably, tend to embrace technologies, such as interactive control andmonitoring, in order to give more assurance of solution correctness.The results presented here demonstrate that even expert CFD users can have significant6-90