Icing-protection requirements for reciprocating-engine induction system (open access)

Icing-protection requirements for reciprocating-engine induction system

From Summary: "Despite the development of relatively ice-free fuel-metering systems, the widespread use of alternate and heated-air intakes, and the use of alcohol for emergency de-icing, icing of aircraft-engine induction systems is a serious problem. Investigations have been made to study and to combat all phases of this icing problem. From these investigations, criterions for safe operation and for design of new induction systems have been established. The results were obtained from laboratory investigations of carburetor-supercharger combinations, wind-tunnel investigations of air scoops, multicylinder-engine studies, and flight investigations. Characteristics of three forms of ice, impact, throttling, and fuel evaporation were studied."
Date: June 20, 1949
Creator: Coles, Willard D.; Rollin, Vern G. & Mulholland, Donald R.
System: The UNT Digital Library
The reversibility theorem for thin airfoils in subsonic and supersonic flow (open access)

The reversibility theorem for thin airfoils in subsonic and supersonic flow

A method introduced by Munk is extended to prove that the light-curve slope of thin wings in either subsonic flow or supersonic flow is the same when the direction of flight of the wing is reversed. It is also shown that the wing reversal does not change the thickness drag, damping-in-roll parameter or the damping-in-pitch parameter.
Date: June 26, 1949
Creator: Brown, Clinton E.
System: The UNT Digital Library
Use of source distributions for evaluating theoretical aerodynamics of thin finite wings at supersonic speeds (open access)

Use of source distributions for evaluating theoretical aerodynamics of thin finite wings at supersonic speeds

From Summary: "A series of publications on the source-distribution methods for evaluating the aerodynamics of thin wings at supersonic speeds is summarized, extended, and unified. Included in the first part are the deviations of: (a) the linearized partial-differential equation for unsteady flow at a substantially constant Mach number. b) The source-distribution solution for the perturbation-velocity potential that satisfies the boundary conditions of tangential flow at the surface and in the plane of the wing; and (c) the integral equation for determining the strength and the location of sources to describe the interaction effects (as represented by upwash) of the bottom and top wing surfaces through the region between the finite wing boundary and the foremost Mach wave. The second part deals with steady-state thin-wing problems. The third part of the report approximates the integral equation for unsteady upwash and includes a solution of approximate equation. Expressions are then derived to evaluate the load distributions for time-dependent finite-wing motions."
Date: June 17, 1949
Creator: Evvard, John C.
System: The UNT Digital Library
Two-dimensional compressible flow in centrifugal compressors with straight blades (open access)

Two-dimensional compressible flow in centrifugal compressors with straight blades

"Six numerical examples are presented for steady, two-dimensional, compressible, nonviscous flow in centrifugal compressors with thin straight blades, the center lines of which generate the surface of a right circular cone when rotated about the axis of the compressor. A seventh example is presented for incompressible flow. The solutions were obtained in a region of the compressors, including the impeller tip, that was considered to be unaffected by the diffuser vanes or by the impeller-inlet configuration" (p. 141).
Date: June 21, 1949
Creator: Stanitz, John D. & Ellis, Gaylord O.
System: The UNT Digital Library
Investigation of Separation of the Turbulent Boundary Layer (open access)

Investigation of Separation of the Turbulent Boundary Layer

"An investigation was conducted on a turbulent boundary layer near a smooth surface with pressure gradients sufficient to cause flow separation. The Reynolds number was high, but the speeds were entirely within the incompressible flow range. The investigation consisted of measurements of mean flow, three components of turbulence intensity, turbulent shearing stress, and correlations between two fluctuation components at a point and between the same component of different points" (p. 1).
Date: June 1, 1949
Creator: Schubauer, G. B. & Klebanoff, P. S.
System: The UNT Digital Library
Correlation of Physical Properties With Molecular Structure for Some Dicyclic Hydrocarbons Having High Thermal-Energy Release Per Unit Volume (open access)

Correlation of Physical Properties With Molecular Structure for Some Dicyclic Hydrocarbons Having High Thermal-Energy Release Per Unit Volume

"As part of a program to study the correlation between molecular structure and physical properties of high-density hydrocarbons, the net heats of combustion, melting points, boiling points, densities, and kinematic viscosities of some hydrocarbons in the 2-n-alkylbiphenyl, 1,1-diphenylalkane, diphenylalkane, 1,1-dicyclohexylalkane, and dicyclohexylalkane series are presented" (p. 55).
Date: June 20, 1949
Creator: Wise, P. H.; Serijan, K. T. & Goodman, I. A.
System: The UNT Digital Library