Reynolds number dependence of the drag coefficient for laminar flow through fine-scale photoetched screens

• Published in: Experiments in fluids Vol. 15; no. 1; pp. 75 - 81
• Main Authors: O'HERN, T. J, TORCZYNSKI, J. R
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.06.1993; Berlin
• Subjects: Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Laminar flows; Physics; Laminar flow; Drag; Screen; Reynolds number; Grid; Photoetching; Numerical simulation; Experimental study
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/BF00195599

The laminar steady flow downstream of fine-mesh screens is studied. Instead of woven-wire screens, high-uniformity screens are fabricated by photoetching holes into 50.8-micron-thick Inconel sheets. The resulting screens have minimum wire widths of 50.8 microns and inter-wire separations of 254 and 318 microns for the two screens examined. A flow facility has been constructed for experiments with these screens. Air is passed through the screens at upstream velocities yielding wire width Reynolds numbers from 2 to 35. To determine the drag coefficient, pressure drops across the screens are measured using pressure transducers and manometers. Three-dimensional flow simulations are also performed. The computational drag coefficients consistently overpredict the experimental values. However, the computational results exhibit sensitivity to the assumed wire cross section, indicating that detailed knowledge of the wire cross section is essential for unambiguous interpretation of experiments using photoetched screens. Standard semiempirical drag correlations for woven-wire screens do not predict the present experimental results with consistent accuracy. (Author (revised))