Serial/Series Title

An analysis of once-per-revolution oscillating aerodynamic thrust loads on single-rotation propellers on tractor airplanes at zero yaw (open access)

An analysis of once-per-revolution oscillating aerodynamic thrust loads on single-rotation propellers on tractor airplanes at zero yaw

A simplified procedure is shown for calculating the once-per-revolution oscillating aerodynamic thrust loads on propellers of tractor airplanes at zero yaw. The only flow field information required for the application of the procedure is a knowledge of the upflow angles at the horizontal center line of the propeller disk. Methods are presented whereby these angles may be computed without recourse to experimental survey of the flow field. The loads computed by the simplified procedure are compared with those computed by a more rigorous method and the procedure is applied to several airplane configurations which are believed typical of current designs. The results are generally satisfactory.
Date: March 21, 1955
Creator: Rogallo, Vernon L.; Yaggy, Paul F. & McCloud, John L., III
System: The UNT Digital Library
Linearized Lifting-Surface and Lifting-Line Evaluations of Sidewash Behind Rolling Triangular Wings at Supersonic Speeds (open access)

Linearized Lifting-Surface and Lifting-Line Evaluations of Sidewash Behind Rolling Triangular Wings at Supersonic Speeds

"The lifting-surface sidewash behind rolling triangular wings has been derived for a range of supersonic Mach numbers for which the wing leading edges remain swept behind the mark cone emanating from the wing apex. Variations of the sidewash with longitudinal distance in the vertical plane of symmetry are presented in graphical form. An approximate expression for the sidewash has been developed by means of an approach using a horseshoe-vortex approximate-lifting-line theory" (p. 455).
Date: October 21, 1955
Creator: Bobbitt, Percy J.
System: The UNT Digital Library
Some Effects of Bluntness on Boundary-Layer Transition and Heat Transfer at Supersonic Speeds (open access)

Some Effects of Bluntness on Boundary-Layer Transition and Heat Transfer at Supersonic Speeds

"Large downstream movements of transition observed when the leading edge of a hollow cylinder or a flat plate is slightly blunted are explained in terms of the reduction in Reynolds number at the outer edge of the boundary layer due to the detached shock wave. The magnitude of this reduction is computed for cones and wedges for Mach numbers to 20. Concurrent changes in outer-edge Mach number and temperature occur in the direction that would increase the stability of the laminar boundary layer. The hypothesis is made that transition Reynolds number is substantially unchanged when a sharp leading edge or tip is blunted" (p. 709).
Date: November 21, 1955
Creator: Moeckel, W. E.
System: The UNT Digital Library