Acceleration, Stress, and Deflection Measurements on the XB-15 Bomber in Gusty Air (open access)

Acceleration, Stress, and Deflection Measurements on the XB-15 Bomber in Gusty Air

From Introduction: "This report presents the results of these tests which cover a total of about 70 flying hours on this airplane."
Date: June 1939
Creator: Pearson, Henry A.
Object Type: Report
System: The UNT Digital Library
Airfoil Theory at Supersonic Speed (open access)

Airfoil Theory at Supersonic Speed

From Summary: "A theory is developed for the airfoil of finite span at supersonic speed analogous to the Prandtl airfoil theory of 1918-1919 for incompressible flow. In addition to the profile and induced drags, account must be taken at supersonic flow of still another drag, namely, the wave drag, which is independent of the wing aspect ratio. Both wave and induced drags are proportional to the square of the lift and depend on the Mach number, that is, the ratio of flight to sound speed. In general, in the case of supersonic flow, the drag-lift ratio is considerably less favorable than is the case for incompressible flow."
Date: June 1939
Creator: Schlichting, H.
Object Type: Report
System: The UNT Digital Library
An approximate spin design criterion for monoplanes (open access)

An approximate spin design criterion for monoplanes

"A quantitative criterion of merit has been needed to assist airplane designers to incorporate satisfactory spinning characteristics into new designs. An approximate empirical criterion, based on the projected side area and the mass distribution of the airplane, has been formulated in a recent British report. In the present paper, the British results have been analyzed and applied to American designs. A simpler design criterion based solely on the type and the dimensions of the tail, has been developed: it is useful in a rapid estimation of whether a new design is likely to comply with the minimum requirements for safety in spinning" (p. 1).
Date: June 1939
Creator: Seidman, Oscar & Donlan, Charles J.
Object Type: Report
System: The UNT Digital Library
Butter Marketing by Cooperative Creameries in the Middle west (open access)

Butter Marketing by Cooperative Creameries in the Middle west

Bulletin discussing
Date: June 1939
Creator: Paul E. Quintus & T. G. Stitts
Object Type: Book
System: The UNT Digital Library
The Calculated Effect of Various Hydrodynamic and Aerodynamic Factors on the Take-Off of a Large Flying Boat (open access)

The Calculated Effect of Various Hydrodynamic and Aerodynamic Factors on the Take-Off of a Large Flying Boat

Present designs for large flying boats are characterized by high wing loading, high aspect ratio, and low parasite drag. The high wing loading results in the universal use of flaps for reducing the takeoff and landing speeds. These factors have an effect on takeoff performance and influence to a certain extent the design of the hull. An investigation was made of the influence of various factors and design parameters on the takeoff performance of a hypothetical large flying boat by means of takeoff calculations.
Date: June 1939
Creator: Olson, R. E. & Allison, J. M.
Object Type: Report
System: The UNT Digital Library
A Comparison of Ignition Characteristics of Diesel Fuels as Determined in Engines and in a Constant-Volume Bomb (open access)

A Comparison of Ignition Characteristics of Diesel Fuels as Determined in Engines and in a Constant-Volume Bomb

Ignition-lag data have been obtained for seven fuels injected into heated, compressed air under conditions simulating those in a compression-ignition engine. The results of the bomb tests have been compared with similar engine data, and the differences between the two sets of results are explained in terms of the response of each fuel to variations in air density and temperature.
Date: June 1939
Creator: Selden, Robert F.
Object Type: Report
System: The UNT Digital Library
A comparison of several tapered wings designed to avoid tip stalling (open access)

A comparison of several tapered wings designed to avoid tip stalling

From Summary: "Optimum proportions of tapered wings were investigated by a method that involved a comparison of wings designed to be aerodynamically equal. The conditions of aerodynamic equality were equality in stalling speed, in induced drag at a low speed, and in the total drag at cruising speed. After the wings were adjusted to aerodynamic equivalence, the weights of the wings were calculated as a convenient method of indicating the optimum wing. The aerodynamic characteristics were calculated from wing theory and test data for the airfoil sections. Various combinations of washout, camber increase in the airfoil sections from the center to the tips, and sharp leading edges at the center were used to bring about the desired equivalence of maximum lift and center-stalling characteristics. In the calculation of the weights of the wings, a simple type of spar structure was assumed that permitted an integration across the span to determine the web and the flange weights. The covering and the remaining weight were taken in proportion to the wing area. The total weights showed the wings with camber and washout to have the lowest weights and indicated the minimum for wings with a taper ratio between 1/2 and 1/3."
Date: June 1939
Creator: Anderson, Raymond F.
Object Type: Report
System: The UNT Digital Library
Cooperative Creamery Accounting (open access)

Cooperative Creamery Accounting

Bulletin discussing methods of installing and maintaining business methods that will be useful to the needs of small cooperative creamery.
Date: June 1939
Creator: Brubaker Delmer D.
Object Type: Book
System: The UNT Digital Library
Cooperative Egg and Poultry Auction Association (open access)

Cooperative Egg and Poultry Auction Association

Bulletin discussing
Date: June 1939
Creator: United States. Weather Bureau.
Object Type: Book
System: The UNT Digital Library
Cooperative Egg Purchasing by Indiana Farmers through Federated County Farm Bureau Associations (open access)

Cooperative Egg Purchasing by Indiana Farmers through Federated County Farm Bureau Associations

Bulletin discussing
Date: June 1939
Creator: Gerald m. Francis
Object Type: Book
System: The UNT Digital Library
The design of fins for air-cooled cylinders (open access)

The design of fins for air-cooled cylinders

From Summary: "An analysis was made to determine the proportions of fins made of aluminum, copper, magnesium, and steel necessary to dissipate maximum quantities of heat for different fin widths, fin weights, and air-flow conditions. The analysis also concerns the determination of the optimum fin proportions when specified limits are placed on the fin dimensions. The calculation of the heat flow in the fins is based on experimentally verified, theoretical equations. The surface heat-transfer coefficients used with this equation were taken from previously reported experiments. In addition to the presentation of fin-design information, this investigation shows that optimum fin dimensions are inappreciably affected by the differences in air flow that are obtained with different air-flow arrangements or by small changes in the length of the air-flow path."
Date: June 28, 1939
Creator: Biermann, Arnold E. & Ellerbrock, Herman H., Jr.
Object Type: Report
System: The UNT Digital Library
Flight Tests of Retractable Ailerons on a Highly Tapered Wing (open access)

Flight Tests of Retractable Ailerons on a Highly Tapered Wing

"A flight investigation was conducted to determine the lateral-control characteristics of retractable ailerons installed on a highly tapered wing. The effectiveness of the ailerons in producing roll was measured at various air speeds with full-span plain flaps both neutral and deflected 45 degrees. The direction of the yawing moment created by the ailerons was also noted. The lateral control provided by the retractable ailerons used in this investigation was approximately the same as that obtained with the plain ailerons of equal span with which the airplane was previously equipped" (p. 1).
Date: June 1939
Creator: Wetmore, J. W.
Object Type: Report
System: The UNT Digital Library
The Hydrodynamic Theory of Detonation (open access)

The Hydrodynamic Theory of Detonation

"This report derives equations containing only directly measurable constants for the quantities involved in the hydrodynamic theory of detonation. The stable detonation speed, D, is revealed as having the lowest possible value in the case of positive material velocity, by finding the minimum of the Du curve (u denotes the speed of the gases of combustion). A study of the conditions of energy and impulse in freely suspended detonating systems leads to the disclosure of a rarefaction front traveling at a lower speed behind the detonation front; its velocity is computed" (p. 1).
Date: June 1939
Creator: Langweiler, Heinz
Object Type: Report
System: The UNT Digital Library
An Investigation of the Drag of Windshields in the 8-Foot High-Speed Wind Tunnel (open access)

An Investigation of the Drag of Windshields in the 8-Foot High-Speed Wind Tunnel

"The drag of closed-cockpit and transport-type windshields was determined from tests made at speeds from 200 to 440 miles per hour in the NACA 8-foot high-speed wind tunnel. This speed range corresponds to a test Reynolds number range of 2,510,000 to 4,830,000 based on the mean aerodynamic chord of the full-span model (17.29 inches). The shapes of the windshield proper, the hood, and the tail fairing were systematically varied to include common types and a refined design" (p. 1).
Date: June 1939
Creator: Robinson, Russell G. & Delano, James B.
Object Type: Report
System: The UNT Digital Library
The Limit of Stability of a Curved Plate Strip Under Shear and Axial Stresses (open access)

The Limit of Stability of a Curved Plate Strip Under Shear and Axial Stresses

"For an infinitely long plate strip of constant curvature there is set up the buckling condition for combined shear and axial stresses. Assumptions are made of the vanishing of the moments acting on the longitudinal edges and of the vanishing of the tangential displacements u and the transverse stresses sigma(sub y) (longitudinal stiffeners nonresistant to bending in the circumferential direction). The buckling condition is evaluated for the case of pure shear and an approximate formula is derived for the critical stresses for large curvatures" (p. 1).
Date: June 1939
Creator: Kromm, A.
Object Type: Report
System: The UNT Digital Library
Monthly Report of the Attorney General of the State of Texas, Volume 1, Number 4, May 1939 (open access)

Monthly Report of the Attorney General of the State of Texas, Volume 1, Number 4, May 1939

Monthly report documenting orders, opinions, and other legal statements issued by the Office of the Attorney General in Texas.
Date: June 1939
Creator: Texas. Attorney-General's Office.
Object Type: Report
System: The Portal to Texas History
Preliminary Report on Laminar-Flow Airfoils and New Methods Adopted for Airfoil and Boundary-Layer Investigations (open access)

Preliminary Report on Laminar-Flow Airfoils and New Methods Adopted for Airfoil and Boundary-Layer Investigations

"Recent developments in airfoil-testing methods and fundamental air-flow investigations, as applied to airfoils, are discussed. Preliminary test results, obtained under conditions relatively free from stream turbulence and other disturbances, are presented. Suitable airfoils and airfoil-design principles were developed to take advantage of the unusually extensive laminar boundary layers that may be maintained under the improved testing conditions" (p. 1).
Date: June 1939
Creator: Jacobs, Eastman N.
Object Type: Report
System: The UNT Digital Library
A preliminary study of the prevention of ice on aircraft by the use of engine-exhaust heat (open access)

A preliminary study of the prevention of ice on aircraft by the use of engine-exhaust heat

"An investigation was made in the N.A.C.A. ice tunnel at air temperatures from 20 degrees to 28 degrees Fahrenheit and at a velocity of 80 miles per hour to determine whether ice formations on a model wing could be prevented by the use of the heat from the engine-exhaust gas. Various spanwise duct systems were tested in a 6-foot-chord N.A.C.A. 23012 wing model. The formation of ice over the entire wing chord was prevented by the direct heating of the forward 10 percent of the wing by hot air, which was passed through leading-edge ducts" (p. 1).
Date: June 1939
Creator: Rodert, Lewis A.
Object Type: Report
System: The UNT Digital Library
Preliminary Tests of Blowers of Three Designs Operating in Conjunction with a Wing-Duct Cooling System for Radial Engines, Special Report (open access)

Preliminary Tests of Blowers of Three Designs Operating in Conjunction with a Wing-Duct Cooling System for Radial Engines, Special Report

"This paper is one of several dealing with methods intended to reduce the drag of present-day radial engine installations and improve the cooling at zero and low air speeds. The present paper describes model wind-tunnel tests of blowers of three designs tested in conjunction with a wing-nacelle combination. The principle of operation involved consists of drawing cooling air into ducts located in the wing root at the point of maximum slipstream velocity, passing the air through the engine baffles from rear to front, and exhausting the air through an annular slot located between the propeller and the engine with the aid of a blower mounted on the spinner" (p. 1).
Date: June 1939
Creator: Biermann, David & Valentine, E. Floyd
Object Type: Report
System: The UNT Digital Library
Tests of Airfoils Designed to Delay the Compressibility Burble (open access)

Tests of Airfoils Designed to Delay the Compressibility Burble

"Development of airfoil sections suitable for high-speed applications has generally been difficult because little was known of the flow phenomenon that occurs at high speeds. A definite critical speed has been found at which serious detrimental flow changes occur that lead to serious losses in lift and large increases in drag. This flow phenomenon, called the compressibility burble, was originally a propeller problem, but with the development of higher speed aircraft serious consideration must be given to other parts of the airplane" (p. 1).
Date: June 1939
Creator: Stack, John
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: O-114 (open access)

Texas Attorney General Opinion: O-114

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: Liability of Purchaser Gathering System for Gross Production Taxes on Pipeline Overage Oil.
Date: June 2, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-129 (open access)

Texas Attorney General Opinion: O-129

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: Title to contributions to Teacher Requirement System.
Date: June 1, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-253 (open access)

Texas Attorney General Opinion: O-253

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification; Whether a License and Weight Inspector has authority to break a lock upon a truck in order to unload the same for the purpose of determining whether such truck carries an excess load.
Date: June 12, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-390 (open access)

Texas Attorney General Opinion: O-390

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: The power of the Railroad Commission to make necessary orders requiring the killing of an uncontrolled gas well, and the remedies for enforcing such orders.
Date: June 9, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History