Serial/Series Title

A Theoretical Investigation of the Drag of Generalized Aircraft Configurations in Supersonic Flow (open access)

A Theoretical Investigation of the Drag of Generalized Aircraft Configurations in Supersonic Flow

"It seems possible that, in supersonic flight, unconventional arrangements of wings and bodies may offer advantages in the form of drag reduction. It is the purpose of this report to consider the methods for determining the pressure drag for such unconventional configurations, and to consider a few of the possibilities for drag reduction in highly idealized aircraft. The idealized aircraft are defined by distributions of lift and volume in three-dimensional space, and Hayes' method of drag evaluation, which is well adapted to such problems, is the fundamental tool employed" (p. 1).
Date: January 1957
Creator: Graham, E. W.; Lagerstrom, P. A.; Licher, R. M. & Beane, B. J.
System: The UNT Digital Library
Turbulence in the Wake of a Thin Airfoil at Low Speeds (open access)

Turbulence in the Wake of a Thin Airfoil at Low Speeds

From Summary: "Experiments have been made to determine the nature of turbulence in the wake of a two-dimensional airfoil at low speeds. The experiments were motivated by the need for data which can be used for analysis of the tail-buffeting problem in aircraft design. Turbulent intensity and power spectra of the velocity fluctuations were measured at a Reynolds number of 1.6 x 10(exp 5) for several angles of attack. Total-head measurements were also obtained in an attempt to relate steady and fluctuating wake properties."
Date: January 1957
Creator: Campbell, George S.
System: The UNT Digital Library
On the Use of the Harmonic Linearization Method in the Automatic Control Theory (open access)

On the Use of the Harmonic Linearization Method in the Automatic Control Theory

"The method of harmonic linearization (harmonic balance), first proposed by N. M. Krylov and N. N. Bogolyubov for the approximate investigation of nonlinear vibrations, has been developed and received wide practical application to problems in the theory of automatic control. Recently, some doubt has been expressed on the legitimacy of application of the method to these problems, and assertions were made on the absence in them of a small parameter of any kind. Nevertheless, the method gives practical, acceptable results and is a simple and powerful means in engineering computations. Hence, the importance of questions arises as to its justification" (p. 1).
Date: January 1957
Creator: Popov, E. P.
System: The UNT Digital Library