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Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel

Description: Report presenting determinations of boundary-layer transition on the NACA 0012 and 23012 airfoils in the high-speed wind tunnel over a range of Reynolds numbers. For all of the lift coefficients that testing occurred at, transition occurred in the region of estimated laminar separation at low Reynolds numbers and approached the point of minimum static pressure as a forward limit at high Reynolds numbers.
Date: January 1940
Creator: Becker, John V.
Item Type: Refine your search to only Report
open access

Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel, Special Report

Description: Determinations of boundary-layer transition on the NACA 0012 and 2301 airfoils were made in the 8-foot high-speed wind tunnel over a range of Reynolds Numbers from 1,600,000 to 16,800,000. The results are of particular significance as compared with flight tests and tests in wind tunnels of appreciable turbulence because of the extremely low turbulence in the high-speed tunnel. A comparison of the results obtained on NACA 0012 airfoils of 2-foot and 5-foot chord at the same Reynolds Number permi… more
Date: January 1940
Creator: Becker, John V.
Item Type: Refine your search to only Report
open access

Mechanical Properties of Flush-Riveted Joints

Description: Report discusses the strength of several types of flush-riveted joints, including single-shearing, double-shearing, and tensile specimens. The stress at failure, type of failure, and d/t ratio are provided. Dimpled joints were found to be the strongest, but their strength was heavily influenced by the details of their construction.
Date: January 1940
Creator: Bruggeman, William C. & Roop, Frederick C.
Item Type: Refine your search to only Report
open access

Propeller Rotation Noise Due to Torque and Thrust

Description: "Sound pressure of the first four harmonics of rotation from a full-scale two-blade propeller were measured and are compared with values calculated from theory. The comparison is made (1) for the space distribution with constant tip speed and (2) for fixed space angles with variable tip speed. A relation for rotation noise from an element of radius developed by Gutin is given showing the effect of number of blades on the rotation noise" (p. 1).
Date: January 1940
Creator: Deming, Arthur F.
Item Type: Refine your search to only Report
open access

Tests of a gust-alleviating flap in the gust tunnel

Description: "Tests were made to determine the effectiveness of a long-period dynamically overbalanced flap in reducing airplane accelerations due to atmospheric gusts. For two gust shapes, one gust velocity, one forward velocity, and one wing loading, a series of flights was made with the flap locked and was then repeated with the flap free to operate. The records were evaluated by routine methods. The results indicate that the flap reduced the maximum acceleration increment 39 percent for a severe gust bu… more
Date: January 1940
Creator: Donely, Philip & Shufflebarger, C. C.
Item Type: Refine your search to only Report
open access

Effect of Wing Loading, Aspect Ratio, and Span Loading of Flight Performances

Description: "An investigation is made of the possible improvements in maximum, cruising, and climbing speeds attainable through increase in the wing loading. The decrease in wing area was considered for the two cases of constant aspect ratio and constant span loading. For a definite flight condition, an investigation is made to determine what loss in flight performance must be sustained if, for given reasons, certain wing loadings are not to be exceeded. With the aid of these general investigations, the tr… more
Date: January 1940
Creator: Göthert, B.
Item Type: Refine your search to only Report
open access

DFS Dive-Control Brakes for Gliders and Airplanes and Analytical Study of the Drag of the DFS Dive-Control Brake

Description: These two reports are surveys on the progress and present state of development of dive-control flaps for gliders and airplanes. The second article describes how on the basis of wind tunnel and free-flight tests, the drag increase on brake flaps of the type DFS, can be predicted. Pressure records confirm a two-dimensional load distribution along the brake-flap surface.
Date: January 1940
Creator: Jacobs, Hans & Wanner, Adolf
Item Type: Refine your search to only Report
open access

Free-spinning wind-tunnel tests of a low-wing monoplane with systematic changes in wings and tails V: effect of airplane relative density

Description: The reported tests are a continuation of an NACA investigation being made in the free-spinning wind tunnel to determine the effects of independent variations in load distribution, wing and tail arrangement, and control disposition on the spin characteristics of airplanes. The standard series of tests was repeated to determine the effect of airplane relative density. Tests were made at values of the relative-density parameter of 6.8, 8.4 (basic), and 12.0; and the results were analyzed. The test… more
Date: January 11, 1940
Creator: Seidman, Oscar & Neihouse, A. I.
Item Type: Refine your search to only Report
open access

Knocking in an Internal-Combustion Engine

Description: The question remains open of the relation between the phenomena of knocking in the engine and the explosion wave. The solution of this problem is the object of this paper. The tests were conducted on an aircraft engine with a pyrex glass window in the cylinder head. Photographs were then taken of various combinations of fuels and conditions.
Date: January 1940
Creator: Sokolik, A. & Voinov, A.
Item Type: Refine your search to only Report
open access

Design Charts Relating to the Stalling of Tapered Wings

Description: An aid in airplane design, charts have been prepared to show the effects of wing taper, thickness ratio, and Reynolds number on the spanwise location of the initial stalling point. Means of improving poor stalling characteristics resulting from certain combinations of the variables have also been considered; additional figures illustrate the influence of camber increase to the wing tips, washout, central sharp leading edges, and wing-tip slots on the stalling characteristics. Data are included … more
Date: January 18, 1940
Creator: Soulé, H. A. & Anderson, R. F.
Item Type: Refine your search to only Report
open access

Effect of body nose shape on the propulsive efficiency of a propeller

Description: Report presents the results of an investigation of the propulsive efficiency of three adjustable propellers of 10-foot diameter operated in front of four body nose shapes, varying from streamline nose that continued through the propeller plane in the form of a large spinner to a conventional open-nose radial-engine cowling. One propeller had airfoil sections close to the hub, the second had conventional round blade shanks, and the third differed from the second only in pitch distribution. The b… more
Date: January 29, 1940
Creator: Stickle, George W.; Crigler, John L. & Naiman, Irven
Item Type: Refine your search to only Report
open access

Constant-Pressure Blowers

Description: "The conventional axial blowers operate on the high-pressure principle. One drawback of this type of blower is the relatively low pressure head, which one attempts to overcome with axial blowers producing very high pressure at a given circumferential speed. The Schicht constant-pressure blower affords pressure ratios considerably higher than those of axial blowers of conventional design with approximately the same efficiency" (p. 1).
Date: January 1940
Creator: Sörensen, E.
Item Type: Refine your search to only Report
open access

The Development of Electrical Strain Gages

Description: "The design, construction, and properties of an electrical-resistance strain gage consisting of fine wires molded in a laminated plastic are described. The properties of such gages are discussed and also the problems of molding of wires in plastic materials, temperature compensation, and cementing and removal of the gages. Further work to be carried out on the strain gage, together with instrument problems, is discussed" (p. 1).
Date: January 1940
Creator: de Forest, A. V. & Leaderman, H.
Item Type: Refine your search to only Report
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