Month

Comparison of Vee-Type and Conventional Tail Surfaces in Combination with Fuselage and Wing in the Variable-Density Tunnel (open access)

Comparison of Vee-Type and Conventional Tail Surfaces in Combination with Fuselage and Wing in the Variable-Density Tunnel

"The pitching and the yawing moments of a vee-type and a conventional type of tail surface were measured. The tests were made in the presence of a fuselage and a wing-fuselage combination in such a way as to determine the moments contributed by the tail surfaces" (p. 1).
Date: July 1941
Creator: Greenberg, Harry
System: The UNT Digital Library
Cooling and Performance Tests of a Continental A-75 Engine (open access)

Cooling and Performance Tests of a Continental A-75 Engine

Note presenting an investigation to determine the performance of a small airplane with two Continental A-75 air-cooled engines enclosed in the wings. The object of the tests was to determine the quantity of air and the pressure difference required for satisfactory cooling of the engine at sea level and at altitude. The engine could be cooled satisfactorily at sea level with wide-open throttle and maximum-power mixture with a pressure difference of 4.5 inches of water and 1.06 pounds of cooling air per second.
Date: July 1941
Creator: Ellerbrock, Herman H., Jr. & Bullock, Robert O.
System: The UNT Digital Library
Correction of the Lifting-Line Theory for the Effect of the Chord (open access)

Correction of the Lifting-Line Theory for the Effect of the Chord

"It is shown that a simple correction for the chord of a finite wing can be deduced from the three-dimensional potential flow around an elliptic plate. When this flow is compared with the flow around a section of an endless plate, it is found that the edge velocity is reduced by the factor 1/E, where E is the ratio of the semiperimeter to the span. Applying this correction to the circulation brings the theoretical lift into closer agreement with experiments" (p. 1).
Date: July 1941
Creator: Jones, Robert T.
System: The UNT Digital Library
Methods of analyzing wind-tunnel data for dynamic flight conditions (open access)

Methods of analyzing wind-tunnel data for dynamic flight conditions

The effects of power on the stability and the control characteristics of an airplane are discussed and methods of analysis are given for evaluating certain dynamic characteristics of the airplane that are not directly discernible from wind tunnel tests alone. Data are presented to show how the characteristics of a model tested in a wind tunnel are affected by power. The response of an airplane to a rolling and a yawing disturbance is discussed, particularly in regard to changes in wing dihedral and fin area. Solutions of the lateral equations of motion are given in a form suitable for direct computations. An approximate formula is developed that permits the rapid estimation of the accelerations produced during pull-up maneuvers involving abrupt elevator deflections.
Date: July 22, 1941
Creator: Donlan, C. J. & Recant, I. G.
System: The UNT Digital Library
The Tensile Elastic Properties at Low Temperatures of 18:8 Cr-Ni Steel as Affected by Heat Treatment and Slight Plastic Deformation (open access)

The Tensile Elastic Properties at Low Temperatures of 18:8 Cr-Ni Steel as Affected by Heat Treatment and Slight Plastic Deformation

Note presenting the relationship between stress, strain, and permanent set for 18:8 Cr-Ni steel as measured at -110 degrees Fahrenheit. The influence of annealing and slight plastic extension upon the derived elastic properties is also discussed.
Date: July 1941
Creator: Mebs, R. W. & McAdam, D. J., Jr.
System: The UNT Digital Library