Clarence W. Matthews
The results of several years experience in the operation of a small water channel have shown that the hydraulic analogy can be used successfully to demonstrate many two-dimensional compressible-flow phenomena. Attempts to use the 20-inch-wide water channel at the Langley Laboratory for research projects, however, led to difficulty in the interpretation of the data with respect to practical flight problems because of the low value of the Reynolds number in the water channel. A channel permitting Reynolds numbers as large as 3,000,000 at tunnel choking would have to be approximately 10 feet wide if the water temperature were 200 degrees F or 20 feet wide if the water temperature were 100 degrees F.
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