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Wind-tunnel tests of single- and dual-rotating pusher propellers having from three to eight blades

Description: Report presenting tests of 10-foot-diameter, single- and dual-rotating pusher propellers with three to eight blades that were conducted in the 20-foot propeller research tunnel as a continuation of previous investigations of tractor propellers. The propellers were mounted at the rear end of a streamline body in spinners that covered the hubs and part of the shanks. The effects as compared to previous testing differed only in degree of effect size.
Date: February 1942
Creator: Gray, W. H.
Partner: UNT Libraries Government Documents Department

Flight Measurements to Determine Effect of a Spring-Loaded Tab on Longitudinal Stability of an Airplane

Description: In conjunction with a program of research on the general problem of stability of airplanes in the climbing condition, tests have been made of a spring-loaded tb which. is referred to as a ?springy tab,? installed on the elevator of a low-wing scout bomber. The tab was arranged to deflect upward with decrease in speed which caused an increase in the pull force required to trim at low speeds and thereby increased the stick-free static longitudinal stability of the airplane. It was found that the springy tab would increase the stick-free stability in all flight conditions, would reduce the danger of inadvertent stalling because of the definite pull force required to stall the airplane with power on, would reduce the effect of center-of-gravity position on stick-free static stability, and would have little effect on the elevator stick forces in accelerated f11ght. Another advantage of the springy tab is that it might be used to provide almost any desired variation of elevator stick force with speed by adjusting the tab hinge-moment characteristics and the variation of spring moment with tab deflection. Unlike the bungee and the bobweight, the springy tab would provide stick-free static stability without requiring a pull force to hold the stick back while taxying. A device similar to the springy tab may be used on the rudder or ailerons to eliminate undesirable trim-force variations with speed.
Date: February 1, 1946
Creator: Hunter, Paul A. & Reeder, John P.
Partner: UNT Libraries Government Documents Department

High-altitude cooling. 3 : Radiators

Description: Report details the methods of determining the heat-transfer rate, pressure drop, and drag power of high-altitude radiators. Performance charts are provided for a wide range of design variables.
Date: September 1944
Creator: Nielsen, Jack Norman
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters 17: experimental inquiry into steady state unidirectional heat-meter corrections

Description: Report divided into two sections. One discusses a correction that must be applied to a heat meter when it is used at temperatures other than temperatures at which it was calibrated. The other section contains the results of an application of the two methods of correcting the heat-transfer rates for contact and heat-meter resistance to experimental data.
Date: August 1944
Creator: Boelter, L. M. K.; Poppendiek, H. F. & Gier, J. T.
Partner: UNT Libraries Government Documents Department