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Aerodynamic Factors Affecting the Ability of a Pilot to Return an Airplane to Level From a Banked Attitude by Use of the Rudder Alone and Without Change of Heading

Description: Report presenting a study of the aerodynamic factors upon which the ability to perform the maneuver depends in an attempt to obtain a better understanding of the conditions involved and, if possible, to evolve criterions that may be used during design.
Date: October 1941
Creator: Harmon, S. M.
Partner: UNT Libraries Government Documents Department

Airfoil Section Data From Tests of 10 Practical-Construction Sections of Helicopter Rotor Blades Submitted by the Sikorsky Aircraft Division, United Aircraft Corporation

Description: Report presenting 10 practical-construction models of sections of helicopter rotor blades tested in the NACA two-dimensional low-turbulence pressure tunnel at atmospheric pressure. Lift, drag, and pitching-moment characteristics of blades representing the present method of construction of the YR-4A helicopter were determined.
Date: September 1944
Creator: Tetervin, Neal
Partner: UNT Libraries Government Documents Department

High-Altitude Cooling 6: Axial-Flow Fans and Cooling Power

Description: Report presenting the theory, design, and effect on cooling of the constant-velocity axial-flow fan as related to the problem of high-altitude aircraft engine cooling. The existing theory of the axial-flow fan, including a discussion of the fan losses, is summarized.
Date: September 1944
Creator: Mutterperl, William
Partner: UNT Libraries Government Documents Department

The Oxidation of Exhaust Gases at Room Temperature

Description: Report presenting an investigation made to determine the effectiveness of various oxides and oxide mixtures in oxidizing at room temperature the exhaust gases from an internal-combustion engine for the determination of fuel-air ratio. The oxides of silver, copper, manganese, cobalt, nickel, iron, cerium, lead, bismuth, and mercury were tested individually and in various combinations.
Date: February 1945
Creator: Gerrish, Harold C.; Meem, J. Lawrence, Jr. & Tuck, Vivian C.
Partner: UNT Libraries Government Documents Department

Measurements of Friction Coefficients in a Pipe for Subsonic and Supersonic Flow of Air

Description: Report presenting tests of the flow of air through brass tubes with the friction coefficient and incompressible flow relation as the main focus. The analytical relation between friction coefficient, tube length, and Mach number is shown for flow without shock and the conditions for flow with and without shock are delimited.
Date: July 1943
Creator: Keenan, Joseph H. & Neumann, Ernest P.
Partner: UNT Libraries Government Documents Department

A Method for the Rapid Estimation of Turbulent Boundary-Layer Thickness for Calculating Profile Drag

Description: "An analysis is developed that makes it possible to integrate von Kármán's boundary-layer momentum equation directly. For this purpose, the skin friction coefficient is expressed as a function of the Reynolds number based on the boundary-layer momentum thickness and the boundary-layer shape is assumed to be constant. The integrated equation permits the boundary-layer momentum thickness at the airfoil trailing edge to be rapidly determined for the estimation of airfoil profile-drag coefficients" (p .1).
Date: July 1944
Creator: Tetervin, Neal
Partner: UNT Libraries Government Documents Department

A Method of Calculating Bending Stresses Due to Torsion

Description: Report presenting a method for analyzing bending stresses due to torsion in a box with variable cross section and loading by means of a recurrence formula leading to a set of equations identical in form with the well-known three-moment equations. An approximate form of the general method of analysis is presented that eliminates the need of solving a system of equations.
Date: December 1942
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

A Method for Welding Sheet Aluminum to SAE 4140 Steel

Description: Report presenting an investigation of a large variety of different metals used as an intermediate metal between aluminum and steel for the purpose of securing a good bond both from the viewpoint of strength and thermal conductivity. The principal result was that it was found possible to secure a satisfactory bond between aluminum and steel by electroplating the steel with a layer of silver of proper thickness.
Date: January 1944
Creator: Hess, W. F. & Nippes, E. F., Jr.
Partner: UNT Libraries Government Documents Department

Method of Calculating Performance of Dual-Rotating Propellers From Airfoil Characteristics

Description: "A method is developed for calculating the performance of a dual-rotating propeller from the section characteristics of the blade elements. The method is applied to an eight-blade dual-rotating propeller and the computed results are compared with low-speed wind-tunnel tests of the same propeller in both the tractor and pusher positions. The computations are found to agree within the experimental accuracy of the measurements" (p. 1).
Date: May 1943
Creator: Naiman, Irven
Partner: UNT Libraries Government Documents Department

Measurements of the Flying Qualities of a Hawker Hurricane Airplane

Description: Report presenting an investigation of the flying qualities of a Hawker Hurricane airplane. Thirteen flights and approximately 17 hours of flying time were required to complete the tests, which included extensive measurements of stability, controllability, and stalling characteristics. The results were similar to the flying qualities of other previously studied pursuit airplanes.
Date: April 1942
Creator: Nissen, J. M. & Phillips, W. H.
Partner: UNT Libraries Government Documents Department

A Method for Studying the Longitudinal Dynamic Stability of Flying-Boat-Hull Models at High Planing Speeds and During Landing

Description: Report presenting an investigation of a method of studying the longitudinal dynamic stability of flying-boat-hull models, as instability may be encountered when flying a flying boat on the water at high speeds and high trim angles, especially upper-limit porpoising and skipping. A method is described for carrying out generalized experimental studies of the longitudinal dynamic stability of flying-boat-hull models.
Date: April 1945
Creator: Locke, F. W. S., Jr. & Hugli, W. C., Jr.
Partner: UNT Libraries Government Documents Department

Preliminary Vibration and Flutter Studies on P-47 Tail

Description: Report presenting a report illustrated by photographs and vibration records on the failure of the P-47 rudder in the high-speed tunnel at a true speed of 468 miles per hour and a density corresponding to 9000 feet altitude. The fin-rudder unit was tested as being at least representative of the tail design of the P-47 airplane.
Date: August 1943
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department

Procedure Used at Aluminum Research Laboratories for Determining Type of Attack in Some Aluminum Alloys

Description: Report presenting samples of 17S-T and 24S-T aluminum alloys subjected to accelerated corrosion tests in which the corrosion period was established at 6 hours for samples that had been etched to produce a uniform surface. The results indicate the types of corrosion attack, which are described in standard terminology, and may form a basis for estimating the resistance of the material to corrosion by a comparison of the relative depth and frequency of the corrosive attacks.
Date: August 1942
Creator: Walton, C. J. & Keller, F.
Partner: UNT Libraries Government Documents Department

Preliminary Report on the Characteristics of the N.A.C.A. 4400R Series Airfoils

Description: Report presenting tests made in the variable-density wind tunnel of airfoils of the NACA 4400 series modified by reflex at the trailing edge designed to reduce the pitching moment to the value of -0.03. The modified airfoils are designated the NACA 4400R series.
Date: March 1939
Creator: Sherman, Albert
Partner: UNT Libraries Government Documents Department

Preliminary Tank Tests With Planing-Tail Seaplane Hulls

Description: Report presenting testing made with simplified models of two types of hulls that differ considerably from conventional types. Both have a single main planing surface that is combined with after-planing surfaces placed directly below the aerodynamic tail surfaces. Results regarding an investigation of twin planing tails, a single-planing tail, and potentialities indicated by tests are provided.
Date: June 1943
Creator: Dawson, John R. & Waldin, Kenneth L.
Partner: UNT Libraries Government Documents Department

The Preparation of 2, 2, 4, 4-Tetramethylpentane

Description: Report presenting seven distinct operations in the preparation of 2,2,4,4-tetramethylpentane, including the preparation of di-isobutylene hydrochloride, preparation of dimethylzinc, reaction of dimethylzinc in dry benzene with di-isobutylene hydrochloride, preliminary distillation of the reaction products, treatment of the first distillate with sodium and alcohol, final distillation after appropriate washing of the products, and recovery of the iodine in the zinc residues of II as methyl iodide.
Date: May 1942
Creator: Drake, N. L.
Partner: UNT Libraries Government Documents Department

A Procedure for the Shear-Lag Analysis of Box Beams

Description: Report presenting a procedure for the shear-lag analysis of box beams, such as wing structures. It is based off of a previous method but allows for the separation of the most essential part of the shear-lag analysis.
Date: January 1943
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

The Propeller and Cooling-Air-Flow Characteristics of a Twin-Engine Airplane Model Equipped With NACA D(Sub S)-Type Cowlings and With Propellers of NACA 16-Series Airfoil Sections

Description: Report presenting an investigation in the 19-foot pressure tunnel to determine the nacelle drag, the cowling-air flow, and the propeller characteristics of a model of a high-performance military airplane. The model is fitted with NACA D(sub S)-type engine cowlings and with propellers embodying NACA 16-series airfoil sections. Results regarding the propeller characteristics, drag and cowling-air flow with the propeller removed, the effect of propeller on flow through cowling, and the influence of cooling requirements on airplane performance are provided.
Date: September 1944
Creator: McHugh, James G. & Pepper, Edward
Partner: UNT Libraries Government Documents Department

Airfoil-Contour Modifications Based on (Epsilon)-Curve Method of Calculating Pressure Distribution

Description: From Introduction: "Certain alternations of a qualitative nature may be performed in spite of the fact that a pressure change cannot be prescribed. It is the purpose of this paper to indicate a method by which qualitative alternation may be performed. It will be noted that the present method of contour modification will serve the intended purpose of the inverse method."
Date: July 1944
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department

Stability and Control Tests of a 3/4-Scale Model of the XP-69 Airplane in the NACA Full-Scale Tunnel

Description: Report presenting tests in the full-scale tunnel to determine the longitudinal- and lateral-stability and control characteristics of a scale model of the XP-69 airplane. The data include measurements of the forces and moments on the model at various angles of attack and angles of yaw. The effects of elevator, rudder, and aileron deflection on control-surface effectiveness and on hinge moments were determined.
Date: January 1943
Creator: Sweberg, Harold H.
Partner: UNT Libraries Government Documents Department