Aerodynamic Characteristics of a Refined Deep-Step Planing-Tail Flying-Boat Hull with Various Forebody and Afterbody Shapes (open access)

Aerodynamic Characteristics of a Refined Deep-Step Planing-Tail Flying-Boat Hull with Various Forebody and Afterbody Shapes

From Introduction: "The results of one phase of this investigation, presented in reference 1, have indicated that hull drag can be reduced without causing large changes in aerodynamic stability and hydrodynamic performance by the use of high length-beam ratios. Another phase of the investigation, reference 2, indicated that hulls of the deep-step planning-tail type have much lower air drag than the conventional type of hull and about the same aerodynamic stability; tank tests, reference 3, have indicated that this type of hull also has hydrodynamic performance equal to and in some respects superior to the conventional type of hull. Unpublished tank tests have indicated that the hull models presented in the present paper (with the possible exception of the forebody alone for which data are not available) will have acceptable hydrodynamic performance."
Date: June 1952
Creator: Riebe, John M. & Naeseth, Rodger L.
System: The UNT Digital Library
The Aerodynamic Design of High Mach Number Nozzles Utilizing Axisymmetric Flow with Application to a Nozzle of Square Test Section (open access)

The Aerodynamic Design of High Mach Number Nozzles Utilizing Axisymmetric Flow with Application to a Nozzle of Square Test Section

From Introduction: "A method for the design of three-dimensional nozzles based on axi-symmetric flow is presented in this paper. The design method presented in this paper is general; however, as an illustrative example of the design of a Mach number 10 nozzle with square test section is included."
Date: June 1952
Creator: Beckwith, Ivan E.; Ridyard, Herbert W. & Cromer, Nancy
System: The UNT Digital Library
Analogue-computer simulation of an autopilot servo system having nonlinear response characteristics (open access)

Analogue-computer simulation of an autopilot servo system having nonlinear response characteristics

From Introduction: "The servo system considered in this report is in the latter category, due mainly to the fact its amplifier tends to saturate. An investigation of the longitudinal dynamic response of the stabilized airplane was made and the results were reported in reference 1. In this investigation it was found that when restricted to linear methods of analysis the performance of the autopilot-aircraft combination could be predicted for only the small range of operation where the elements of the autopilot operated within their linear range."
Date: June 1952
Creator: Jones, Arthur L. & White, John S.
System: The UNT Digital Library
An Analysis of Supersonic Flow in the Region of the Leading Edge of Curved Airfoils, Including Charts for Determining Surface-Pressure Gradient and Shock-Wave Curvature (open access)

An Analysis of Supersonic Flow in the Region of the Leading Edge of Curved Airfoils, Including Charts for Determining Surface-Pressure Gradient and Shock-Wave Curvature

Note presenting an investigation of the inviscid flow in the region of the leading edge of curved airfoils with attached shock waves. Tables and charts are presented for determining the surface-pressure gradient and the shock-wave curvature in supersonic flow of an ideal diatomic gas. An approximate procedure for determining the flow field a short distance downstream of the leading edge is also presented.
Date: June 1952
Creator: Kraus, Samuel
System: The UNT Digital Library
An approximate method of determining the subsonic flow in an arbitrary stream filament of revolution cut by arbitrary turbomachine blades (open access)

An approximate method of determining the subsonic flow in an arbitrary stream filament of revolution cut by arbitrary turbomachine blades

Report presenting a method to obtain a relatively quick approximate determination of the detailed subsonic flow of a nonviscous fluid past arbitrary turbomachine blades. The method is illustrated with examples of compressible flow in a turbine cascade and in a centrifugal compressor.
Date: June 1952
Creator: Wu, Chung-Hua; Brown, Curtis A. & Prian, Vasily D.
System: The UNT Digital Library
Calculation of lift and pitching moments due to angle of attack and steady pitching velocity at supersonic speeds for thin sweptback tapered wings with streamwise tips and supersonic leading and trailing edges (open access)

Calculation of lift and pitching moments due to angle of attack and steady pitching velocity at supersonic speeds for thin sweptback tapered wings with streamwise tips and supersonic leading and trailing edges

Report presenting a derivation for a series of thin sweptback tapered wings with streamwise tips and supersonic leading and trailing edges. The results of the analysis are presented as a series of design charts. Results regarding formulas and computations for several derivatives, chordwise center-of-pressure location, and extensions of the results by the use of reversibility theorems are provided.
Date: June 1952
Creator: Martin, John C.; Margolis, Kenneth & Jeffreys, Isabella
System: The UNT Digital Library
Comparison of Three Multicylinder Icing Meters and Critique of Multicylinder Method (open access)

Comparison of Three Multicylinder Icing Meters and Critique of Multicylinder Method

"Three multicylinder cloud meters, fundamentally similar but differing in important details, were compared in use at the Mount Washington Observatory. Determinations of liquid water content were found to agree within the limits of the probable error, but the two instruments designed by the National Advisory Committee for Aeronautics indicated larger drop sizes than did the Observatory's instrument, apparently because of spurious ice catch on the rather rough surface of the larger cylinders. Comparisons of drop-size distribution were largely indeterminate" (p. 1).
Date: June 1952
Creator: Howell, Wallace E.
System: The UNT Digital Library
Displacement Effect of a Three-Dimensional Boundary Layer (open access)

Displacement Effect of a Three-Dimensional Boundary Layer

Note presenting a method for determining the displacement surface of a known three-dimensional compressible boundary-layer flow in terms of the mass-flow defects associated with the profiles of the two velocity components parallel to the surface. The analysis deals only with the displacement effect of a known boundary layer on the nonviscous outer flow, and can only be applied if the boundary-layer behavior has been determined either theoretically or experimentally.
Date: June 1952
Creator: Moore, Franklin K.
System: The UNT Digital Library
Effect of Compressor-Outlet Air Bleed on Performance of a Centrifugal-Flow Turbojet Engine with a Constant-Area Jet Nozzle (open access)

Effect of Compressor-Outlet Air Bleed on Performance of a Centrifugal-Flow Turbojet Engine with a Constant-Area Jet Nozzle

Note presenting the effect of compressor-outlet air bleed on turbojet engine performance, which is calculated by the use of an analysis based on experimentally determined component characteristics of a centrifugal-flow turbojet engine with a constant-area jet nozzle. A range of engine speeds from 0.9 to 1.0 of rated engine speed and air-bleed rates fro 0 to 0.10 of compressor air flow are considered at a flight Mach number of 0.52 and an altitude of 24,000 feet. Results regarding the effect of air bleed on pumping characteristics and effect of air bleed on engine performance are provided.
Date: June 1952
Creator: Huntley, Sidney C.
System: The UNT Digital Library
Effect of Open Circular Holes on Tensile Strength and Elongation of Sheet Specimens of a Magnesium Alloy (open access)

Effect of Open Circular Holes on Tensile Strength and Elongation of Sheet Specimens of a Magnesium Alloy

Note presenting an investigation of the effect of open circular holes on the tensile strength and elongation of sheet specimens of magnesium alloy AM-C52S in both the annealed and hard-rolled condition. Tests were made to study the effect of variable ratio of hole diameter to total specimen width and the effect of spacing and arrangement of the holes.
Date: June 1952
Creator: Barker, R. S.
System: The UNT Digital Library
Effect of Temperatures From -70 to 600 Degrees Fahrenheit on Strength of Adhesive-Bonded Lap Shear Specimens of Clad 24S-T3 Aluminum Alloy and of Cotton-and Glass-Fabric Plastic Laminates (open access)

Effect of Temperatures From -70 to 600 Degrees Fahrenheit on Strength of Adhesive-Bonded Lap Shear Specimens of Clad 24S-T3 Aluminum Alloy and of Cotton-and Glass-Fabric Plastic Laminates

Report presenting an evaluation of the performance of 14 commercial adhesives at a range of temperatures in lap shear specimens of clad 24S-T aluminum alloy to itself and that of 7 commercial adhesives at a range of temperatures in lap joints of cotton-fabric-phenolic laminate to itself, of glass-fabric-polyester laminate to itself, and in joints of each of these laminates to clad aluminum. Results regarding aluminum to aluminum joints and plastic to plastic and plastic to aluminum joints are provided.
Date: June 1952
Creator: Eickner, H. W.; Olson, W. Z. & Blomquist, R. F.
System: The UNT Digital Library
Fatigue and Static Tests of Flush-Riveted Joints (open access)

Fatigue and Static Tests of Flush-Riveted Joints

Note presenting fatigue tests at zero mean load on 190 multiple-rivet joints with 1/8 inch diameter A17S-T3 100 degree countersunk-head rivets. Joints made by dimpling showed marked superiority in both fatigue and static strengths to those made by machine countersunking. The relationships between measured static properties of lap joints and fatigue life for the four materials are given.
Date: June 1952
Creator: Howard, Darnley M. & Smith, Frank C.
System: The UNT Digital Library
Fatigue Strengths of 14S-T4 Aluminum Alloy Subjected to Biaxial Tensile Stresses (open access)

Fatigue Strengths of 14S-T4 Aluminum Alloy Subjected to Biaxial Tensile Stresses

Note presenting an investigation to determine the influence of biaxial tensile stresses on the fatigue strength of a 14S-T4 aluminum alloy when subjected to various ratios of biaxial stresses. The effect on the fatigue strength of varying the ratio of the biaxial stresses was studied. Anisotropy of the material was found to be the main characteristics that affected fatigue strength.
Date: June 1952
Creator: Marin, Joseph & Hughes, W. P.
System: The UNT Digital Library
Flow characteristics over a lifting wedge of finite aspect ratio with attached and detached shock waves at a Mach number of 1.40 (open access)

Flow characteristics over a lifting wedge of finite aspect ratio with attached and detached shock waves at a Mach number of 1.40

From Summary: "A series of schileren photographs and pressure distributions are presented which show the effects of transition from an attached to a detached shock at the leading edge of a finite-span, 8.2 degree wedge as the angle of attack is increased. These data were obtained in the Langley 4- by 4-foot supersonic tunnel at a Mach number of 1.40."
Date: June 1952
Creator: Hilton, John H., Jr.
System: The UNT Digital Library
Influence of structure on properties of sintered chromium carbide (open access)

Influence of structure on properties of sintered chromium carbide

Report presenting an investigation to study the influence of structural variations on the properties of chromium carbide sintered under pressure. The results show that the room-temperature strength and hardness are influenced by the stages of sintering, which are defined by grain size and by the number, size, location, and shape of pores.
Date: June 1952
Creator: Hamjian, H. J. & Lidman, W. G.
System: The UNT Digital Library
Interaction of Oblique Shock Waves With Regions of Variable Pressure, Entropy, and Energy (open access)

Interaction of Oblique Shock Waves With Regions of Variable Pressure, Entropy, and Energy

Note presenting equations for computing the form of an oblique shock wave as it passes through supersonic regions in which static pressure, stagnation pressure, stagnation temperature, or combinations of these are continuously variable.
Date: June 1952
Creator: Moeckel, W. E.
System: The UNT Digital Library
Investigation of Statistical Nature of Fatigue Properties (open access)

Investigation of Statistical Nature of Fatigue Properties

Note presenting an experimental program to study the subject of metal fatigue and to determine and evaluate the fundamental factors which influence the behavior. The statistics of the fatigue-fracture curves and endurance limits were determined for a variety of metals and the effects of some metallurgical factors on the statistical nature of fatigue properties were shown.
Date: June 1952
Creator: Epremian, E. & Mehl, R. F.
System: The UNT Digital Library
Method for calculation of heat transfer in laminar region of air flow around cylinders of arbitrary cross section (including large temperature differences and transpiration cooling) (open access)

Method for calculation of heat transfer in laminar region of air flow around cylinders of arbitrary cross section (including large temperature differences and transpiration cooling)

Report presenting a method permitting the calculation of local heat transfer around the periphery of cylinders of arbitrary cross section in the laminar region for flow of a fluid with constant property values with an accuracy sufficient for engineering purposes. The method is applied to circular and elliptic cylinders are the results are described.
Date: June 1952
Creator: Eckert, E. R. G. & Livingood, John N. B.
System: The UNT Digital Library
Normal Accelerations and Operating Conditions Encountered by a Helicopter in Air-Mail Operations (open access)

Normal Accelerations and Operating Conditions Encountered by a Helicopter in Air-Mail Operations

Note presenting an analysis of the normal accelerations and operating conditions encountered by a single-rotor helicopter engaged in air-mail operations in the vicinity of Los Angeles and its suburbs over a period of 14 months. The results indicate that, for this type of operation, maneuver loads developed in routine flight are often greater than the largest gust loads.
Date: June 1952
Creator: Crim, Almer D. & Hazen, Marlin E.
System: The UNT Digital Library
On the Application of Transonic Similarity Rules (open access)

On the Application of Transonic Similarity Rules

Note presenting a discussion of the transonic aerodynamic characteristics of wings of finite span from the point of view of a unified small perturbation theory for subsonic, transonic, and supersonic flows about thin wings. The relation between the two methods of analysis of transonic flow is examined, the similarity rules and known solutions of transonic flow theory are reviewed, and the asymptotic behavior of the lift, drag, and pitching-moment characteristics of wings of large and small aspect ratio are discussed.
Date: June 1952
Creator: Spreiter, John R.
System: The UNT Digital Library
Theoretical analysis of hydrodynamic impact of a prismatic float having freedom in trim (open access)

Theoretical analysis of hydrodynamic impact of a prismatic float having freedom in trim

From Summary: "Equations which include freedom in trim are derived for hydrodynamic impact of a non-chine-immersed, prismatic float forebody having a V-bottom and a transverse step. These equations are an extension of previously published fixed-trim theory, and a method of solution is indicated by which time histories of vertical, horizontal, and angular displacement, velocity, and acceleration can be obtained. Comparisons of specific solutions of the equations with corresponding fixed-trim solutions are presented."
Date: June 1952
Creator: Miller, Robert W.
System: The UNT Digital Library
Theoretical Investigation of Velocity Diagrams of a Single-Stage Turbine for a Turbojet Engine at Maximum Thrust Per Square Foot Turbine Frontal Area (open access)

Theoretical Investigation of Velocity Diagrams of a Single-Stage Turbine for a Turbojet Engine at Maximum Thrust Per Square Foot Turbine Frontal Area

Note presenting an exploratory velocity-diagram analysis made in order to establish the aerodynamic requirements of a single-stage, axial-flow turbine which satisfies the conditions of maximum thrust per square foot of turbine frontal area in a turbojet engine. The investigation was made over a range of turbine mean blade speeds and inlet temperatures, fixed flight conditions, and a constant centrifugal stress at the root of the rotor blading. A comparison was made employing conventional turbine aerodynamic design limits for one set of conditions from the analysis.
Date: June 1952
Creator: Cohen, Leo
System: The UNT Digital Library
Theory of Supersonic Potential Flow in Turbomachines (open access)

Theory of Supersonic Potential Flow in Turbomachines

"A general method for solving supersonic potential flow problems for stationary or rotating coordinate systems is presented. The principal attributes of the method are: It can handle flows which cannot be treated as two-dimensional, and a sound theoretical basis gives assurance of its validity for a class of boundary-value problems. An application to the design of a compressor rotor is made" (p. 1).
Date: June 1952
Creator: Wasserman, Robert H.
System: The UNT Digital Library
Transonic similarity rules for lifting wings (open access)

Transonic similarity rules for lifting wings

Report presenting the use of similarity rules for the transonic flow about lifting wings are derived by considering the change in the flow field due to angle of attack as a small perturbation to the nonlifting flow field. It has an advantage over other approaches because the effects of angle of attack and airfoil geometry are partially separated.
Date: June 1952
Creator: Harder, Keith C.
System: The UNT Digital Library