CFD simulation of the Effects of Some Operational Parameterson the Performance of a Local Exhaust Ventilation in thePresence of Human Movement

In local exhaust ventilation systems, external turbulence from e.g. human movements can affect the captureefficiency of the system considerably. In this study, numerical (CFD) approaches were utilized to evaluate theeffect of human movement on the capture efficiency of a local exhaust ventilation system with an exteriorcircular hood. Human movements were simulated by back-and-forth movements of a human-sized moving flatplate. The numerical simulations included dynamic mesh methods to handle object movements. The numericalresults had reasonable agreement with experimental results regarding the capture efficiency at differentmovement frequencies and exhaust flow rates, indicating that CFD is a feasible method for investigatingcomplex flows of the studied kind. Further, effects of some operational parameters on the capture efficiencywere evaluated. The results indicated that the magnitude with which capture efficiency increases by increasingthe exhaust air flow rate and movement time interval, and also by decreasing the distance between contaminantsource and exhaust hood opening. Further, increasing the distance between the movable object and thecontaminant source, as well as decreasing the diameter of the exhaust hood opening increased the captureefficiency.

کلیدواژه ها:

LEV ، Human Movement ، Tracer Gas Method ، Capture Efficiency