Modelling convective currents in rooms by means of wall jets

Abstract

Most assessments of air movements in proposed rooms are made on the bases of manufacturers' information, simple design predictions and experience. However with respect to those designs for which the performance has to be guaranteed (e.g. hospital operating theatres), experimental investigations are usually necessary using either relatively large mock-ups or small-scale models. The former are expensive, but doubts exist concerning the credibility of predictions obtained via measurements made with models. The present theoretical study has shown that the representation of convective currents in rooms (e.g. as generated by windows and domestic ‘radiators’) by plane jets in models is feasible, and numerical recommendations that will enable a designer to achieve this replacement are proposed. This investigation required a detailed analysis of what happens in the initial region of the plane jet to be undertaken in order to be able to match the air flows in the model to those in the full-size room.