Development of a new pressure drop correlation for open-cell foams based completely on theoretical grounds: Taking into account strut shape and geometric tortuosity

In Search of Governing Gas Flow Mechanism through Metal Solid Foams

“…It is clear that the literature results cannot predict the flow behavior for all foams with acceptable accuracy. The equations differ greatly, thus producing significant scatter: while for one foam the model prediction is acceptable, (e.g., Inayat et al [12] describes the Al 40 PPI foam satisfactorily (Figure 2b)), it fails for other foams, as shown in Figure 2a for the Al 10 PPI foam. It is probably, as suggested also by Dietrich [14], connected with the proper determination of the specific surface area and other morphological parameters of the solid foams.…”

“…The other problem is the proper determination of the cross-sectional shape of the strut. This shape determines the constant value in the correlation proposed by Inayat et al [12]. Taking into account the porosity for Al 20 PPI foam (0.91), according to the authors [12], it should have a circular cross section of the strut (for ε < 0.92-0.93), but it is rather close to a triangle (compare the strut cross section shown in Figure 1).…”

“…This shape determines the constant value in the correlation proposed by Inayat et al [12]. Taking into account the porosity for Al 20 PPI foam (0.91), according to the authors [12], it should have a circular cross section of the strut (for ε < 0.92-0.93), but it is rather close to a triangle (compare the strut cross section shown in Figure 1). Therefore, the literature correlations do not suit all the experimental results well enough, although a detailed selected literature equation might approach the experimental results for foam examined with acceptable accuracy.…”

“…Moreover, the foam skeleton can be solid or porous, with the pores either open or closed to the foam void space [10,11]. Many correlations describing the flow resistance (∆P/H) for different solid foams exist in the literature (e.g., [1,[11][12][13][14]). However, most display serious divergences upon comparison (see e.g., Dietrich [14]).…”

Pressure drop in liquid chromatography

“…None of previously mentioned correlations accurately describe pressure drop on such beds. Because of that several alternative correlations were proposed taking into account specific microstructure of particular convective media [101][102][103][104][105][106][107][108][109][110][111][112][113][114].…”