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Investigation of Diving Moments of a Pursuit Airplane in the Ames 16-Foot High Speed Wind Tunnel

Description: From Summary: "A pursuit type airplane encountered severe diving moments in high-speed dives which make recovery difficult. For the purpose of investigating these diving moments and finding means for their reduction, a 1/6 scale model of the airplane was tested in the 16-foot high-speed wind tunnel at Ames Aeronautical Laboratory. The test results indicate that up to a Mach number of at least 0.75, the limit of the tests, the dive-recovery difficulties can be alleviated and the longitudinal maneuverability improved by the substitution of a long symmetrical fuselage for the standard fuselage."
Date: October 1942
Creator: Erickson, Albert L.
Partner: UNT Libraries Government Documents Department

Considerations of wake-excited vibratory stress in a pusher propeller

Description: Report presenting an equation based on simple blade-element theory and the assumption of a fixed wake pattern is derived and fitted to available data to show the first-order relation between the parameters of propeller operation and intensity of wake-excited periodic force acting on the blades of a pusher propeller. The derived equation indicates that the effect of power coefficient on the intensity of the wake-excited periodic force is small. Limited data also indicates that the wake-excited vibratory stress in a propeller increases with the drag of the body producing the wake.
Date: February 1944
Creator: Corson, Blake W., Jr.
Partner: UNT Libraries Government Documents Department

Preliminary flight research on an all-movable horizontal tail as a longitudinal control for flight at high Mach numbers

Description: Report presenting flight tests of an all-movable horizontal tail installed on a Curtiss XP-42 airplane due to its possible advantages as a longitudinal control at high Mach numbers. The elevator control was found to be unsatisfactory with the control arrangements tested.
Date: March 1945
Creator: Kleckner, Harold F.
Partner: UNT Libraries Government Documents Department

Preliminary Investigation in the NACA Low-Turbulence Tunnel of Low-Drag Airfoil Sections Suitable for Admitting Air at the Leading Edge

Description: From Summary: "An investigation was carried out in the NACA low-turbulence tunnel to develop low-drag airfoil sections suitable for admitting air at the leading edge. A thickness distribution having the desired type of pressure distribution was found from tests of a flexible model. Other airfoil shapes were derived from this original shape by varying the thickness, the camper, the leading-edge radius, and the size of the leading-edge opening. Data are presented giving the characteristics of the airfoil shapes in the range of lift coefficients for high-speed and cruising flight."
Date: July 1942
Creator: von Doenhoff, Albert E. & Horton, Elmer A.
Partner: UNT Libraries Government Documents Department

Preliminary experimental investigation of airfoils in cascade

Description: Report presenting information about airfoils in cascade, including the angle through which the air is turned and where the cascade losses are located.
Date: July 1942
Creator: Kantrowitz, Arthur & Daum, Fred L.
Partner: UNT Libraries Government Documents Department

Measurements of flying qualities of a Curtiss SB2C-1 airplane (number 00014)

Description: Report presenting an investigation of the flying qualities of a Curtiss SB2C-1 airplane. Tests were made to determine the effect of a bobweight in the elevator system and the effect of seals in the aileron gaps. Results regarding longitudinal stability and control, requirements for lateral stability and control, and stalling characteristics are provided.
Date: March 1944
Creator: Phillips, W. H.; Williams, W. C. & Hoover, H. H.
Partner: UNT Libraries Government Documents Department

Flame-visibility tests with individual exhaust stacks

Description: Report presenting testing made on a Wright 1820-G single-cylinder engine to determine the effect of operating variables and the effect of shape and size of the exhaust stack on the visibility of exhaust gases for individual-stack installations. Flame damping was improved by decrease in nozzle-exit area, increase in stack length, and reduction in hydraulic diameter of the exhaust jets. Results regarding the characteristics of exhaust flames and damping of exhaust flames are provided.
Date: February 1944
Creator: Turner, L. Richard & Humble, Leroy V.
Partner: UNT Libraries Government Documents Department

Flight tests of two airplanes having moderately high effective dihedral and different directional stability and control characteristics

Description: Report presenting flight tests of a twin-engine midwing attack bomber and a single-engine low-wing fighter, which indicate that both have moderately high effective dihedral but different directional stability and control characteristics. The pilots had a harder time controlling the fighter airplane, while the attack bomber was found to have a higher degree of directional stability and low directional trim forces, which the pilots preferred.
Date: October 1945
Creator: Sjoberg, S. A.
Partner: UNT Libraries Government Documents Department

Flight tests of beveled-trailing-edge ailerons with various modifications on a North American XP-51 airplane (AAF No.41-38)

Description: Report presenting flight testing using a North American XP-51 airplane with several arrangements of beveled-trailing-edge ailerons to determine the most satisfactory arrangement. Results regarding the aileron configuration, trimming tabs, and factors affecting symmetry of aileron characteristics are provided.
Date: December 1943
Creator: White, Maurice D. & Hoover, Herbert H.
Partner: UNT Libraries Government Documents Department

Flight Tests of Modifications to Improve the Aileron Control Characteristics of a North American XP-51 Airplane (AC No. 41-38)

Description: Investigations were undertaken to improve the ailerons of a P-51 fighter so as to obtain greater effectiveness without increasing the stick forces. Modifications consisted of increasing the deflection range of the aileron to 70 percent and changing the original concave section to a thick section with beveled trailing edge. Results of the modified ailerons showed an increase in effectiveness over the original aileron of 70 percent at low speed and 55 percent at high speeds.
Date: June 1942
Creator: White, M. D. & Hoover, Herbert H.
Partner: UNT Libraries Government Documents Department

Wind-tunnel data on the aerodynamic characteristics of airplane control surfaces

Description: Report presenting lift and hinge-moment characteristics of various types of airplane control surface. The data can be used to determine curves correlating the results of many tests of the various types of aerodynamic balance.
Date: December 1943
Creator: Sears, Richard I.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigation of a Low-Drag Airfoil Section with a Double Slotted Flap

Description: From Summary: "Tests were made of an 0.309-chord double-slotted flap on an NACA 65, 3-118, a equals 1.0 airfoil section to determine drag, lift, and pitching-moment characteristics for a range of flap deflections. Results indicate that combination of a low-drag airfoil and a double-slotted flap, of which the two parts moved as a single unit, gave higher maximum lift coefficients than have been obtained with plain, split, or slotted flaps on low-drag airfoils. Pitching moments were comparable to those obtained with other high-lift devices on conventional airfoils for similar lift coefficients."
Date: September 1943
Creator: Bogdonoff, Seymour M.
Partner: UNT Libraries Government Documents Department

Wind tunnel investigation of control surface characteristics 9: some analytical considerations and experimental test results for an internally balanced flap

Description: Report presenting an analysis of the probable aerodynamic section characteristics of a plain flap with various arrangements of internal balance. The results of the calculations previously obtained were found to be in agreement with the experiment. Some possible applications of the data to balancing tabs are also provided.
Date: July 1942
Creator: Sears, Richard I.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of control-surface characteristics 1: effect of gap on the aerodynamic characteristics of an NACA 0009 airfoil with a 30-percent-chord plain flap

Description: From Summary: "Tests have been made to determine the effect of a gap at the flap nose upon the aerodynamic section characteristics of an NACA 0009 airfoil with a plain flap and tab. The results are presented in the form of airfoil and flap section characteristics for several flap deflections, tab deflections, and for four sizes of gap."
Date: June 1941
Creator: Sears, Richard I.
Partner: UNT Libraries Government Documents Department

Full-scale wind-tunnel and flight tests of a Fairchild XR2K-1 airplane with a zap flap and upper-surface aileron-wing installation

Description: Report presenting testing of a Fairchild XR2K-1 airplane equipped with a wing having a full-span Zap flap and upper-surface ailerons in the full-scale wind tunnel and in flight to determine the characteristics of the flap and ailerons. Results regarding the lift, drag, and pitching-moment coefficients of the airplane and the aileron rolling, yawing, and hinge-moment coefficients were measured at various flap deflections are provided. Maximum rolling velocity and acceleration, yawing velocity, time lag in aileron response, and aileron control forces were also determined.
Date: March 1942
Creator: Clousing, L. A.; Lehr, Robert R. & O'Sullivan, William J.
Partner: UNT Libraries Government Documents Department

Wind-tunnel tests of single- and dual-rotating tractor propellers of large blade width

Description: Report presenting tests of 10-foot diameter, single- and dual-rotating tractor propellers with two to eight blades conducted in the 20-foot propeller-research tunnel. The blades were 50 percent wider than those used in previous investigations. Results regarding the effect of dual rotation and effect of solidity are provided.
Date: September 1942
Creator: Biermann, David; Gray, W. H. & Maynard, Julian D.
Partner: UNT Libraries Government Documents Department

Operating stresses in aircraft-engine crankshafts and connecting rods 2: instrumentation and test results

Description: Report presenting an investigation to develop methods and equipment for the measurement of operating stresses in aircraft-engine crankshafts and connecting rods. The results indicate that the measurement of stresses in connecting rods is feasible. Results regarding stresses in the crankshaft and stresses in the master connecting rod are provided.
Date: August 1945
Creator: Dutee, Francis J.; Phillips, Franklyn W. & Calvert, Howard F.
Partner: UNT Libraries Government Documents Department

The effect of exhaust-stack shape on the design and performance of the individual cylinder exhaust-gas jet-propulsion system

Description: Report presenting tests on a single-cylinder, air-cooled engine to determine the effect of several different exhaust-stack shapes on the design and performance of the individual cylinder exhaust-gas jet-propulsion systems. Results regarding the effect of nozzle area and stack shape on exhaust-gas jet thrust, effect of nozzle area and stack shape on overall performance for the S-shape, the 90 degree bend, and the 180 degree bend, the effect on the shape on engine power and volumetric efficiency, and the effect of a branched stack on engine power are provided.
Date: November 1942
Creator: Turner, L. Richard & Humble, Leroy V.
Partner: UNT Libraries Government Documents Department

The effect of external shape upon the drag of a scoop

Description: Report presenting testing of six scoops built using the principles of NACA cowling design to show the advantage of using those principles. Three scoops had a good nose contour with different afterbody lengths and three were of inferior nose shape. Results regarding drag, cooling pressure, and surface pressure survey are provided.
Date: July 1941
Creator: Naiman, Irven & Hill, Paul R.
Partner: UNT Libraries Government Documents Department

Determination of desirable lengths of Z- and channel-section columns for local-instability tests

Description: From Summary: "Local-instability tests of 24S-T aluminum-alloy formed Z- and channel-section columns were made in order to determine a length of test specimen that would avoid the increased strength associated with short lengths and also permit the occurrence of a convenient buckling pattern. The effect of column length on the critical compressive stress, on the average stress at maximum load, and on the number of half-waves of the buckling pattern is shown."
Date: October 1944
Creator: Heimerl, George J. & Roy, J. Albert
Partner: UNT Libraries Government Documents Department

The effect of cooling-air blowers on thrust power

Description: Report presenting an analysis of the effect of cooling-air blowers on thrust power using an assumed airplane. Results indicated that when aviation-engine heat exchangers are used above their design altitude, blowers may be used to give additional available pressure and to increase jet thrust. Results regarding airplane speed, altitude, fin width, physical significance of the heat cycle, and thermodynamic efficiency are provided.
Date: July 1944
Creator: Palmer, Carl B. & Brevoort, Maurice J.
Partner: UNT Libraries Government Documents Department

The effect of dead rise upon the high-angle porpoising characteristics of two planing surfaces in tandem

Description: Report presenting porpoising tests of three rudimentary models composed of two V-bottom planing surfaces in tandem and fitted with a tail plane. The upper and lower branches of the upper trim limit of stability were determined for three angles of dead rise and two depths of step.
Date: June 1943
Creator: Benson, James M. & Klein, Milton M.
Partner: UNT Libraries Government Documents Department

Effect of changing the stroke on air capacity, power output and detonation of a single-cylinder engine

Description: Report presenting an investigation of a special single-cylinder test engine constructed with provision for operation with three different lengths of piston stroke. Results regarding the air capacity of the engine, extent to which the spark must be retarded in order to prevent detonation, and brake mean effective pressure are provided.
Date: February 1945
Creator: Livengood, James C. & Eppes, James V. D.
Partner: UNT Libraries Government Documents Department

A method for studying piston friction

Description: From Introduction: "The purpose of this investigation was to develop a method for determining directly the friction force between the piston and cylinder of an internal combustion engine. The method consists in elastically mounting the cylinder barrel so that it can have a small motion parallel to its axis, and providing suitable means for recording its instantaneous displacement."
Date: March 1943
Creator: Forbes, J. E. & Taylor, E. S.
Partner: UNT Libraries Government Documents Department