The measurement of fluctuations of air speed by the hot-wire anemometer (open access)

The measurement of fluctuations of air speed by the hot-wire anemometer

"The hot-wire anemometer suggests itself as a promising method for measuring the fluctuating air velocities found in turbulent flow. The only obstacle is the presence of a lag due to the limited energy input which makes even a fairly small wire incapable of following rapid fluctuations with accuracy. This paper gives the theory of the lag and describes an experimental arrangement for compensating for the lag for frequencies up to 100 or more per second when the amplitude of the fluctuation is not too great. An experimental test of the accuracy of compensation and some results obtained with the apparatus in a wind-tunnel air stream are described. While the apparatus is very bulky in its present form, it is believed possible to develop a more portable arrangement" (p. 359).
Date: January 8, 1929
Creator: Dryden, H. L. & Kuethe, A. M.
System: The UNT Digital Library
Characteristics of Five Propellers in Flight (open access)

Characteristics of Five Propellers in Flight

"This investigation was made for the purpose of determining the characteristics of five full-scale propellers in flight. The equipment consisted of five propellers in conjunction with a VE-7 airplane and a Wright E-2 engine. The propellers were of the same diameter and aspect ratio. Four of them differed uniformly in thickness and pitch and the fifth propeller was identical with one of the other four with exception of a change of the airfoil section" (p. 267).
Date: November 8, 1927
Creator: Crowley, J. W., Jr. & Mixson, R. E.
System: The UNT Digital Library