A Concise Theoretical Method for Profile-Drag Calculation; Advance Report (open access)

A Concise Theoretical Method for Profile-Drag Calculation; Advance Report

In this report a method is presented for the calculation of the profile drag of airfoil sections. The method requlres only a knowledge of the theoretical velocity distribution and can be applied readily once this dlstribution is ascertained. Comparison of calculated and experimental drag characteristics for several airfoils shows a satisfactory agreement. Sample calculatlons are included.
Date: February 1944
Creator: Nitzberg, Gerald E.
System: The UNT Digital Library
Wind-Tunnel Investigation of Control-Surface Characteristics: [Part] 18 - A Linked Overhang Aerodynamic Balance (open access)

Wind-Tunnel Investigation of Control-Surface Characteristics: [Part] 18 - A Linked Overhang Aerodynamic Balance

Report presenting wind-tunnel testing in two-dimensional flow to investigate the aerodynamic characteristics of a flap balanced by a large overhang linked to deflect more slowly than the flap. Three lengths of blunt-nose overhang were tested linked to a 0.30-airfoil-chord straight-contour flap on an NACA 66-009 airfoil. Results regarding lift, hinge moment, drag, pitching moment, and practical considerations are provided.
Date: February 1944
Creator: Sears, Richard I. & Liddell, Robert B.
System: The UNT Digital Library
Flight Investigation of Boundary-Layer Control by Suction Slots on an NACA 35-215 Low-Drag Airfoil at High Reynolds Numbers (open access)

Flight Investigation of Boundary-Layer Control by Suction Slots on an NACA 35-215 Low-Drag Airfoil at High Reynolds Numbers

Report presenting an investigation of the effectiveness of suction slots as a means of extending the laminar boundary layer in flight at high Reynolds numbers on an NACA 35-215 airfoil. The results showed that, with a slot spacing of about 5 percent of the chord, the laminar boundary layer could be maintained to or slightly beyond 45 percent of the chord.
Date: February 1944
Creator: Zalovcik, John A.; Wetmore, J. W. & von Doenhoff, Albert E.
System: The UNT Digital Library
Knock-limited performance of several internal coolants (open access)

Knock-limited performance of several internal coolants

Report presenting the effect of internal cooling on the knock-limited performance of AN-F-28 fuel in a CFR engine with the following internal coolants: water, methyl alcohol-water mixture, ammonia-methyl alcohol-water mixture, monomethyllamine-water mixture, dimethylamine-water mixture, and trimethylamine-water mixture.
Date: February 1944
Creator: Bellman, Donald R. & Evvard, John C.
System: The UNT Digital Library
Flight investigation of boundary-layer control by suction slots on an NACA 35-215 low-drag airfoil at high Reynolds numbers (open access)

Flight investigation of boundary-layer control by suction slots on an NACA 35-215 low-drag airfoil at high Reynolds numbers

Report presenting an investigation of the effectiveness of suction slots a a means of extending the laminar boundary layer in flight at high Reynolds numbers using an NACA 35-215 airfoil. Tests were made over a range of indicated airspeeds, lift coefficients, and Reynolds numbers. Results regarding boundary-layer control, air-intake distributions, character of the boundary layer, total-intake rate, and profile-drag coefficient are provided.
Date: February 1944
Creator: Zalovcik, John A.; Wetmore, J. W. & von Doenhoff, Albert E.
System: The UNT Digital Library
The Determination of Span Load Distribution at High Speeds by Use of High-Speed Wind-Tunnel Section Data (open access)

The Determination of Span Load Distribution at High Speeds by Use of High-Speed Wind-Tunnel Section Data

Report presenting a tabular method for determining the span load distribution at high Mach numbers by utilizing high-speed airfoil section data. This method, which is also called the generalized method, is an easily applied process of successive approximations by which a general application of the lifting-line theory may be used to determine the span load distribution for wings composed of sections with arbitrary lift curves. An example is provided to show how the method is used.
Date: February 1944
Creator: Boshar, John
System: The UNT Digital Library
Comparison of calculated and experimental propeller characteristics for four-, six-, and eight-blade single-rotating propellers (open access)

Comparison of calculated and experimental propeller characteristics for four-, six-, and eight-blade single-rotating propellers

Report presenting the calculated performance of four-, six-, and eight-blade single-rotating propellers compared with experimental results for blade angles ranging from 25 to 65 degrees. The data were obtained on propellers mounted in front of a streamline body with a spinner housing the hub.
Date: February 1944
Creator: Crigler, John L.
System: The UNT Digital Library
Considerations of wake-excited vibratory stress in a pusher propeller (open access)

Considerations of wake-excited vibratory stress in a pusher propeller

Report presenting an equation based on simple blade-element theory and the assumption of a fixed wake pattern is derived and fitted to available data to show the first-order relation between the parameters of propeller operation and intensity of wake-excited periodic force acting on the blades of a pusher propeller. The derived equation indicates that the effect of power coefficient on the intensity of the wake-excited periodic force is small. Limited data also indicates that the wake-excited vibratory stress in a propeller increases with the drag of the body producing the wake.
Date: February 1944
Creator: Corson, Blake W., Jr.
System: The UNT Digital Library