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Investigation of flutter characteristics of three low-aspect-ratio all-movable half-span control surfaces at Mach numbers from 1.49 to 2.87

Description: Report presenting the results of a supersonic flutter investigation of three low-aspect-ratio control surfaces, two which had all-movable controls and one with a fixed cutout. Experimental results are provided and compared to calculations using the piston theory for plan form 2. Modifications for improving the flutter of the various control surfaces are also described.
Date: May 2, 1958
Creator: Morgan, Homer G.; Figge, Irving E. & Presnell, John G., Jr.
Partner: UNT Libraries Government Documents Department

Methods for measuring temperatures of thin-walled gas-turbine blades

Description: The accuracy and durability of two means for measuring the metal temperature of gas-turbine blades were investigated experimentally in a turbojet engine. Cemented thermocouples that could be placed in walls as thin 0.010 inch and commercial temperature-indicating paints were evaluated at turbine-inlet temperatures up to about 1650 degrees F and for centrifugal forces equivalent to about 42,000 times gravity. The cemented thermocouples operated satisfactorily. The temperature-indicating paints were neither as accurate nor as durable as the cemented thermocouples.
Date: November 2, 1956
Creator: Stepka, Francis S & Hickel, Robert O
Partner: UNT Libraries Government Documents Department

Nonmetallic Material Compatibility with Liquid Fluorine

Description: Static tests were made on the compatibility of liquid fluorine with several nonmetallic materials at -3200 F and at pressures of 0 and 1500 pounds per square inch gage. The results are compared with those from previous work with gaseous fluorine at the same pressures, but at atmospheric temperature. In general, although environmental effects were not always consistent, reactivity was least with the low-temperature, low-pressure liquid fluorine. Reactivity was greatest with the warm, high-pressure gaseous fluorine. None of the liquids and greases tested was found to be entirely suitable for use in fluorine systems. Polytrifluorochloroethylene and N-43, the formula for which is (C4F9)3N, did not react with liquid fluorine at atmospheric pressure or 1500 pounds per square inch gage under static conditions, but they did react when injected into liquid fluorine at 1500 pounds per square inch gage; they also reacted with gaseous fluorine at 1500 pounds per square inch gage. While water did not react with liquid fluorine at 1500 pounds per square inch gage, it is known to react violently with fluorine under other conditions. The pipe-thread lubricant Q-Seal did not react with liquid fluorine, but did react with gaseous fluorine at 1500 pounds per square inch gage. Of the solids, ruby (Al2O3) and Teflon did not react under the test conditions. The results show that the compatibility of fluorine with nonmetals depends on the state of the fluorine and the system design.
Date: October 2, 1957
Creator: Price, Harold G , Jr & Douglass, Howard W
Partner: UNT Libraries Government Documents Department

The effects at subsonic speeds of wing fences and a tail on the longitudinal characteristics of a 63 degree swept-wing fuselage combination

Description: Report presenting wind-tunnel testing to evaluate the effects of wing fences and a tail on the longitudinal characteristics of a highly swept wing in combination with a fuselage. The model, which had a cambered and twisted wing with a leading-edge sweepback of 63 degrees and an aspect ratio of 3.5, was tested with fences of various shapes and swept and unswept horizontal tails. Results regarding exploratory tests, final-configuration tests, static longitudinal stability factors, and maximum lift-drag ratios are provided.
Date: July 2, 1957
Creator: Buell, Donald A. & Kolbe, Carl D.
Partner: UNT Libraries Government Documents Department

Analysis of effects of airplane characteristics and autopilot parameters on a roll-command system with aileron rate and deflection limiting

Description: From Summary: "The dynamic characteristics of an airplane with a proportional-gain roll-control autopilot are discussed. A comparison of three different high-speed fighter airplanes is presented. The dynamic effects of time lags and various gains in the system are described."
Date: September 2, 1955
Creator: Schy, Albert A. & Gates, Ordway B., Jr.
Partner: UNT Libraries Government Documents Department

Investigation of mechanical fastenings for solid turbine blades made from ductile materials

Description: Report presenting rupture testing conducted on tensile specimens of fir-tree turbine blade root fastenings for three specific turbojet engines. Testing was conducted at temperatures from 0 degrees to 1500 degrees. Results regarding the short-time tests at various temperatures, long-time stress-rupture tests at 1200 degrees Fahrenheit, long-time tests at increased temperature, and remarks on the criteria for using the fir-tree root design are provided.
Date: August 2, 1954
Creator: Meyer, André J., Jr.; Kaufman, Albert & Caywood, W. C.
Partner: UNT Libraries Government Documents Department