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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

Wind-tunnel investigation of control-surface characteristics 17: beveled-trailing-edge flaps of 0.20, 0.30, and 0.40 airfoil chord on an NACA 0009 airfoil

Description: Report presenting force tests in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the aerodynamic characteristics of an NACA 0009 airfoil with flaps having chord at 3 locations of the airfoil chord and three degrees of the beveled trailing edges. The results indicated that, with a smooth leading edge, the increased trailing-edge angle on the flaps with sealed gaps decreased the slope of the control-fixed lift curve and the lift effectiveness.
Date: April 1944
Creator: Lockwood, Vernard E.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of control-surface characteristics 13: various flap overhangs used with a 30-percent-chord flap in an NACA 66-009 airfoil

Description: Report presenting force tests in two-dimensional flow made on an NACA 66-009 airfoil with a flap having a chord 30 percent of the airfoil chord and a tab having a chord 20 percent of the flap chord. A plain flap and flaps having overhangs of 35 and 50 percent of the flap chord were tested with two gap variations: sealed and unsealed. Results regarding lift, flap hinge moments, pitching moments, drag, and tab characteristics are provided.
Date: July 1943
Creator: Gillis, Clarence L.
Partner: UNT Libraries Government Documents Department

Flight Investigation at High Speeds of Profile Drag of Wing of a P-47D Airplane Having Production Surfaces Covered with Camouflage Paint

Description: Wing section outboard of flap was tested by wake surveys in Mach range of 0.25 - 0.78 and lift coefficient range 0.06 - 0.69. Results indicated that minimum profile-drag coefficient of 0.0097 was attained for lift coefficients from 0.16 to 0.25 at Mach less than 0.67. Below Mach number at which compressibility shock occurred, variations in Mach of 0.2 had negligible effect on profile drag coefficient. Shock was not evident until critical Mach was exceeded by 0.025.
Date: March 1946
Creator: Zalovcik, John A. & Daum, Fred L.
Partner: UNT Libraries Government Documents Department

Free-spinning-tunnel tests of a 1/23.75-scale model of the Douglas DC-3 airplane

Description: Report presenting testing of a model of the Douglas DC-3 airplane for several loading conditions. The load factor for the complete airplane, for the horizontal tail, and the force to start moving the elevator downward were estimated for some steady spins. Testing occurred at 2500 feet and 10,000 feet.
Date: June 1942
Creator: MacDougall, George F., Jr.
Partner: UNT Libraries Government Documents Department

Wind Tunnel Investigation of the Effects of Slot Shape and Flap Location on the Characteristics of a Low-Drag Airfoil Equipped with a 0.25-Chord Slotted Flap

Description: Tests were conducted at dynamic pressure of 50 lb per square foot with lift drag and pitch moment measurements throughout useful angle of attack range for constant flap deflection and position of a low-drag airfoil. Two slots were investigated and practical flap paths were selected for each Slot shape had a negligible effect on the maximum lift coefficient flap deflected, the rounded-entry slot had lower profile drag.
Date: December 1944
Creator: Holtzclaw, Ralph W. & Weisman, Yale
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of ailerons on a low-drag airfoil 1: The effect of aileron profile

Description: Report presenting an investigation in the 7- by 10-foot wind tunnel of the effects of various modifications to the profile of a 0.20-chord plain sealed aileron and a 0.15-chord plain sealed aileron on an NACA 66,2-216 airfoil. Thickening of the aileron was found to reduce the aileron effectiveness, reduce the slope of the wing section lift curve, and reduce the hinge-moment coefficients. Results regarding the section data, aileron effectiveness, aileron hinge moments, lift, pitching moment, drag, and Reynolds number are provided.
Date: January 1944
Creator: Crane, Robert M. & Holtzclaw, Ralph W.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of ailerons on a low-drag airfoil 2: the effect of thickened and beveled trailing edges

Description: Report presenting an investigation in the 7- by 10-foot wind tunnel of the effects of modifications to the trailing edge of a 0.20-chord plain sealed aileron on an NACA 66,2-216 airfoil. The modifications considered consisted of various amounts of symmetrical thickening and beveling of the aileron trailing edge. Results regarding aileron effectiveness, aileron hinge moments, aileron control forces, lift, pitching moment, drag, and Reynolds number are provided.
Date: January 1944
Creator: Crane, Robert M. & Holtzclaw, Ralph W.
Partner: UNT Libraries Government Documents Department

Tests of two models representing intermediate inboard and outboard wing sections of the XB-36 airplane

Description: Report presenting testing in the two-dimensional low-turbulence pressure tunnel and the two-dimensional low-turbulence tunnel of two models made by the Consolidated Aircraft Corporation, one of the outboard section and one of the inboard section.
Date: January 1943
Creator: Bogdonoff, Seymour M.
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

An investigation of aircraft heaters 15: the emissivity of several materials

Description: Report presenting a determination of the mean effective emissivity as a function of temperature for the surfaces of several metals and insulating materials. A description and discussion of the measuring technique is presented. The results are plotted on a variety of graphs.
Date: January 1944
Creator: Boelter, L. M. K.; Bromberg, R. & Gier, J. T.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters 14: an air and heat flow analysis of a ram-operated heater and duct system

Description: Report presenting a method of graphical analysis that allows for the prediction of the thermal and aerodynamic performance of a ram-operated heater and duct system, for cabin heating or wing de-icing, at any altitude and airplane speed. Performance can be predicted from the isothermal total pressure drop across the components of the duct system at several ventilating air rates and the thermal output of the heater at various air and exhaust gas rates.
Date: March 1944
Creator: Boelter, L. M. K.; Morrin, E. H.; Martinelli, R. C. & Poppendiek, H. F.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters 24: the heat meter in the transient state for unidirectional heat transfer

Description: Report describing the behavior of the heat meter when it is used in thermal circuits which are under the influence of transient potentials. Three scenarios are considered: a heat meter suddenly placed on a hot surface, a heat meter mounted on the interior surface of the cabin wall of an uninsulated airplane climbing through air of decreasing temperature, and a heat meter mounted on the interior surface of the composite cabin wall of an airplane climbing through air of decreasing temperature.
Date: September 1944
Creator: Boelter, L. M. K.; Poppendiek, H. F.; Dunkle, R. V. & Gier, J. T.
Partner: UNT Libraries Government Documents Department

Measurements in flight of the pressure distribution on the right wing of a P-39N-1 airplane at several values of Mach number

Description: Report presenting pressure-distribution measurements made on the right wing of a P-39N-1 airplane at values of Mach number up to 0.80. A considerable portion of the lift was carried by components of the airplane other than the wings, and the proportion carried by the wing varies considerably with Mach number. Results regarding the variation of wing loads and moments with Mach number, internal wing pressure, and airplane lift-curve slope are provided.
Date: April 1945
Creator: Clousing, Lawrence A.; Turner, William N. & Rolls, L. Stewart
Partner: UNT Libraries Government Documents Department

Tests of Four Full-Scale Propellers to Determine the Effect of Trailing-Edge Extensions on Propeller Aerodynamic Characteristics

Description: Propellers with trailing-edge extensions were studied to determine aerodynamic characteristics. Trailing-edge extension increased power absorbed by propeller with little loss in efficiency. Power coefficient for maximum efficiency was greater for 20% camber type extension than for 20% straight type extension over range of advance ratio of 1.0 to 2.5 although camber type was less efficient. Efficiency was about the same for cruising and high-speed at a high power coefficient for propeller with extension.
Date: July 1945
Creator: Maynard, Julian D. & Evans, Albert J.
Partner: UNT Libraries Government Documents Department

Wind-tunnel tests of four full-scale seaplane floats

Description: Report presenting wind tunnel testing of four full-scale seaplane floats to determine the aerodynamic characteristics of the floats and to evaluate several drag-reducing refinements. Four floats were investigated; two differed only in external details like flush rivets, while one was the type used on twin-float installations. The variation of lift, drag, and pitching moment with pitch angle are presented for each float.
Date: July 1943
Creator: Conway, Robert N. & Maynard, Julian D.
Partner: UNT Libraries Government Documents Department

Quantitative analysis for aromatic amines in aviation fuels by ultraviolet spectrophotometry

Description: From Summary: "A method of quantitative analysis for individual aromatic amines or mixtures of aromatic amines in hydrocarbon fuel blends by spectrophotometric measurement of ultraviolet-light absorption is presented. The effect of the precision of the spectrophotometric measurements, the purity of the aromatic amine, photochemical decomposition of the amine, and the composition of the fuel on the accuracy of the analysis is discussed and the results of tests of the precision of the procedure are given."
Date: November 1945
Creator: Tischler, Adelbert O.
Partner: UNT Libraries Government Documents Department

Loss of xylidines in overwater storage of xylidine-blended fuel

Description: Tests were undertaken to determine the relationships for estimating the maximum amount of a water-soluble gasoline additive that will diffuse from the gasoline to the water when fuel is stored over the water and to determine from the relationships the amount of xylidines that will diffuse from the gasoline to the water in an overwater-storage system.
Date: March 1944
Creator: Tischler, Adelbert O. & Tischler, Adelbert O.
Partner: UNT Libraries Government Documents Department

Performance tests of NACA type A finned-tube exhaust heat exchanger

Description: Report presenting tests to determine the thermal and pressure-drop performance and durability of a cross-flow, internally finned, tubular exhaust-heat exchanger. The test covered a range of exhaust-gas flows, cooling-air flows, and exhaust-gas temperatures.
Date: August 1944
Creator: Reuter, J. George & Manson, S. V.
Partner: UNT Libraries Government Documents Department

Oxygen boosting of an aircraft-engine cylinder in conjunction with internal coolants

Description: Report presenting an investigation to determine the possibility of attaining or approaching critical-altitude power at altitudes considerably higher than the critical as limited by the supercharger by the use of oxygen in conjunction with internal coolants.
Date: April 1944
Creator: Spencer, Robert C.; Jones, Anthony W. & Pfender, John F.
Partner: UNT Libraries Government Documents Department

Performance of compressor-turbine jet-propulsion systems

Description: Report presenting an analysis of the performance of compressor-turbine jet-propulsion systems carried out by calculating the thrust power from a compressor-turbine jet engine with a systematic variation of pressure ratio, fuel-air ratio, compressor and turbine efficiencies, flight speed, altitude, and maximum gas temperature.
Date: June 1945
Creator: Palmer, Carl B.
Partner: UNT Libraries Government Documents Department

Effects of trailing-edge modifications on pitching moment characteristics of airfoils

Description: Report presenting an analysis of the available data on the effects of trailing-edge modifications on the pitching-moment characteristics of airfoils. Some of the variables explored include the location of the airfoil aerodynamic center and variation of pitching-moment coefficient with control-surface deflection are provided.
Date: September 1944
Creator: Purser, Paul E. & Johnson, Harold S.
Partner: UNT Libraries Government Documents Department

Wind-tunnel vibration tests of dual-rotating propellers

Description: Report presenting vibration tests of six- and eight-blade tractor and seven- and eight-blade pusher dual-rotating propellers conducted in the 16-foot high-speed tunnel to determine the severity of vibrations excited by blade passages. Measurements of vibratory stresses were made for engine-speed ranges at low, intermediate, and high engine powers. Few vibrations caused by blade passages were detected, and those vibrations were not serious.
Date: September 1943
Creator: Miller, Mason F.
Partner: UNT Libraries Government Documents Department