C. A. PILOT TUBE orifices of the Pitot tube as Figure 5. The curves show the existence of a considerable scale effect, as might be expected from the shape of the resistance coefficient curve for cylinders in that VI range, and there is, also, indication of a critical interference at about 3 inches… … the reversal does not appear in the data from the high speed run, the effect is attributed to the slight form irregularity. The maximum error in head found under these conditions being only 6.5% (3.4% in velocity), the interference curves have not been plotted on abscissae of rod diameter units…
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