Important secondary effects in gaseous magnetic filtration

The important dimensionless parameters A, W, Ksin an idealized single wire HGMF model (neglecting gravitational effects) are not adequate in a real filter. The influence of other important secondary parameters in a random HGMF filter consisting of rectangular wires was investigated. Average dimensionless wire separation and the dimensionless filter length were found to be important. Two effects are associated with wire closeness, viz. wire-wire and flow field interference. Decreasing wire separation reduces the strength and gradient of the local magnetic field, and also increases wire shadowing; all of these reduce particle capture. Near the front of the filter, reduced wire separation increases the intensity of transverse flow fluctuations which enhance capture. However, as a fully turbulent flow field developes along the filter length, this disadvantage is lost so that the extra filter length is less effective. Rectangular wire with a higher aspect ratio shows reduced capture radius for otherwise identical conditions. However, because of the lower A parameter for these higher aspect ratios, magnetic interference effects are reduced.