AN INSTRUMENT FOR THE STUDY OF AERODYNAMIC FLOWS

摘要

Considerable progress in aerodynamic studies has resulted from the application of instruments measuring flow parameters.nThe hot wire, pitot tube, interferometer, and schlieren-photographntechniques have all proved to be invaluable assets in these studies.nEach of these techniques has application in various free streamnvelocity ranges, the entire range going from supersonic to subsonicnflow speeds.nThe instrument described below was designed to determinenquantitatively one flow parameter (the density) within the boundsnof the following requirements:n1) It was to be applicable throughout the entire free stream velocity range of all the techniques listed above.n2) It was to extend considerably the lower free stream velocity limit of any of the techniques listed above.n3.) It was -not to interact with the flow pattern to such a degree that it would make the information obtained as a result of accomplishing requirement 2) difficult to interpret.