Performance of Axial Fans in Close Proximity to the Electromagnetic

The performance of axial fans in close proximity to the electromagnetic compatibility(EMC) screens was analyzed by means of an experimental parametric study. The follow-ing geometrical parameters were studied: the hub-to-tip ratio, the ratio between fanthickness and fan diameter, the porosity and thickness of the perforated plate, and finally,the distance between the perforated plate and the inlet and the outlet of the fan. Screenporosity was found to be the most important parameter. Fan performance degradation isexpressed by means of two correlations: one for the deterioration in the fan pressure atthe no-flow point and the other for the flow rate reduction at the free delivery point. Bothcorrelations were formulated as functions of screen porosity and the distance betweenthe fan and the screen. We believe that the correlations can serve as a good guide for cor-rect fan placement in a telecommunications cabinet. [DOI: 10.1115/1.4005913]Keywords: fan characteristic curve, telecommunications cabinet, perforated plate,