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Hydrodynamic and aerodynamic tests of models of floats for single-float seaplanes NACA models 41-D, 41-E, 61-A, 73, and 73-A

Description: Tests were made in the NACA tank and in the NACA 7 by 10 foot wind tunnel on two models of transverse step floats and three models of pointed step floats considered to be suitable for use with single float seaplanes. The object of the program was the reduction of water resistance and spray of single float seaplanes without reducing the angle of dead rise believed to be necessary for the satisfactory absorption of the shock loads. The results indicated that all the models have less resistance an… more
Date: July 1938
Creator: Parkinson, J. B. & House, R. O.
Item Type: Refine your search to only Report
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Hydrodynamic and aerodynamic tests of models of flying-boat hulls designed flow aerodynamic drag - NACA models 74, 74-A, and 75

Description: The present tests illustrate how the aerodynamic drag of a flying boat hull may be reduced by following closely the form of a low drag aerodynamic body and the manner in which the extent of the aerodynamic refinement is limited by poorer hydrodynamic performance. This limit is not sharply defined but is first evidenced by an abnormal flow of water over certain parts of the form accompanied by a sharp increase in resistance. In the case of models 74-A and 75, the resistance (sticking) occurs onl… more
Date: October 1938
Creator: Truscott, Starr; Parkinson, J. B.; Ebert, John W., Jr. & Valentine, E. Floyd
Item Type: Refine your search to only Report
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Implements and Methods of Tillage to Control Soil Blowing on the Northern Great Plains

Description: This bulletin tools and methods of tilling which can help reduce or control soil blowing and soil erosion on farms in the northern Great Plains of the United States. Among the crops discussed with relation to tilling methods are beans, corn, sorghum, potatoes, alfalfa, and sweet clover.
Date: 1938
Creator: Cole, John S. (John Selden) & Morgan, George W.
Item Type: Refine your search to only Pamphlet
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Improvement of aileron effectiveness by the prevention of air leakage through the hinge gap as determined in flight

Description: "A flight investigation was made of the increase in effectiveness of ailerons that can be obtained by preventing flow of air through the wing at the hinges and of the possibility of reducing the aileron operating force by replacing ailerons having normal open hinge gaps with narrower but equally effective ailerons having sealed hinge gaps. Tests were made with a Fairchild 22 airplane with two sizes of plain unbalanced ailerons, one set having a chord equal to 0.18c, and the other chord equal to… more
Date: January 1938
Creator: Soulé, H. A. & Gracey, W.
Item Type: Refine your search to only Report
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The increase in frictional resistance caused by various types of rivet heads as determined by tests of planing surfaces

Description: "The increase in the frictional resistance of a surface caused by the presence of rivet heads was determined by towing four planing surfaces of the same dimensions. One surface was smooth and represented a surface without rivet heads or one with perfectly flush countersunk rivets. The other three surfaces were each fitted with the same number of full-size rivet heads but of a different type arranged in the same pattern on each surface" (p. 1).
Date: May 1938
Creator: Truscott, Starr & Parkinson, J. B.
Item Type: Refine your search to only Report
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Infectious Anemia (Swamp Fever)

Description: Infectious anemia (which is also known as swamp fever) is a disease which afflicts horses and mules and results in significant financial losses for farms every year. This bulletin discusses the causes and forms of the disease, the accompanying anatomical changes in infected animals, the diagnostic process, and control measures which can be taken to prevent further spread of this serious illness.
Date: 1938
Creator: Gochenour, William S. (William Sylva), b. 1891; Stein, C. D. (Clarence Dinsmore), b. 1889 & Osteen, Oswald L. (Oswald Lamont), b. 1908
Item Type: Refine your search to only Pamphlet
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The influence of directed air flow on combustion in spark-ignition engine

Description: "The air movement within the cylinder of the NACA combustion apparatus was regulated by using shrouded inlet valves and by fairing the inlet passage. Rates of combustion were determined at different inlet-air velocities with the engine speed maintained constant and at different engine speeds with the inlet-air velocity maintained approximately constant. The rate of combustion increased when the engine speed was doubled without changing the inlet-air velocity; the observed increase was about the… more
Date: October 10, 1938
Creator: Rothrock, A. M. & Spencer, R. C.
Item Type: Refine your search to only Report
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The influence of lateral stability on disturbed motions of an airplane with special reference to the motions produced by gusts

Description: "Distributed lateral motions have been calculated for a hypothetical small airplane with various modifications of fin area and dihedral setting. Special combinations of disturbing factors to simulate gusts are considered and the influence of lateral stability on the motions is discussed. Fin area and wing dihedral were found to be of primary importance in side gusts. It was found that the rolling action of the wing with as much as 5 degrees dihedral was distinctly unfavorable, especially when t… more
Date: June 8, 1938
Creator: Jones, Robert T.
Item Type: Refine your search to only Report
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The Influence of Notches Under Static Stress

Description: From the described experiments it is seen that notches are a potential source of strength decrease even under static stress, which the designer must take into consideration. Section I is a general treatment of notch influence under the various types of stresses. Section II treats the influence of notches in thin sheet as is used in airplane construction.
Date: May 1938
Creator: Matthaes, K.
Item Type: Refine your search to only Report
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Interference of Tail Surfaces and Wing and Fuselage from Tests of 17 Combinations in the N.A.C.A. Variable-Density Tunnel

Description: "An investigation of the interference associated with tail surfaces added to wing-fuselage combinations was included in the interference program in progress in the NACA variable-density tunnel. The results indicate that, in aerodynamically clean combinations, the increment of the high-speed drag can be estimated from section characteristics within useful limits of accuracy. The interference appears mainly as effects on the downwash angle and as losses in the tail effectiveness and varies with t… more
Date: November 5, 1938
Creator: Sherman, Albert
Item Type: Refine your search to only Report
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Interference of Wing and Fuselage From Tests of 17 Combinations in the N.A.C.A. Variable-Density Tunnel Combination With Special Junctures

Description: "As part of the wing-fuselage interference program in progress in the NACA variable-density wind tunnel, a method of eliminating the interference bubble associated with critical mid wing combinations was investigated. The interference bubble of the critical mid wing combination was shown to respond to modification at the nose of the juncture and to be entirely suppressed with little or no adverse effect on the high-speed drag by special leading edge fillets" (p. 1).
Date: March 1938
Creator: Sherman, Albert
Item Type: Refine your search to only Report
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Interference of Wing and Fuselage From Tests of Eight Combinations in the N.A.C.A. Variable-Density Tunnel Combinations With Tapered Fillets and Straight-Side Junctures

Description: "The round fuselage of an unfilleted low-wing combination was modified to incorporate straight-side junctures. The resulting combination, with or without horizontal tail surfaces, had practically the same aerodynamic characteristics as the corresponding round-fuselage tapered-fillet combination" (p. 1).
Date: March 1938
Creator: Sherman, Albert
Item Type: Refine your search to only Report
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Interference of Wing and Fuselage From Tests of the 18 Combinations in the N.A.C.A. Variable-Density Tunnel - Combination With Split Flaps

Description: "As part of the wing-fuselage interference investigation in progress in the N.A.C.A. variable density wind tunnel, the effects of various split-flap arrangements applied to wing-fuselage combinations were determined. Split flaps were found to exert their influence independently of the interference, and their effects on the aerodynamic characteristics of rectangular-airfoil combinations appeared to be more or less proportional to their exposed span lengths. The interference, moreover, showed the… more
Date: March 1938
Creator: Sherman, Albert
Item Type: Refine your search to only Report
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Investigation in the 7-by-10 Foot Wind Tunnel of Ducts for Cooling Radiators within an Airplane Wing

Description: Report presents the results of an investigation made in the NACA 7 by 10-foot wind tunnel of a large-chord wing model with a duct to house a simulated radiator suitable for a liquid-cooled engine. The duct was expanded to reduce the radiator losses, and the installation of the duct and radiator was made entirely within the wing to reduce form and interference drag. The tests were made using a two-dimensional-flow setup with a full-span duct and radiator. Section aerodynamic characteristics of t… more
Date: June 9, 1938
Creator: Harris, Thomas A. & Recant, Isidore G.
Item Type: Refine your search to only Report
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Investigation in the 7-By-10 Foot Wind Tunnel of Ducts for Cooling Radiators Within an Airplane Wing, Special Report

Description: "An investigation was made in the NACA 7- by 10-foot wind tunnel of a large-chord wing model with a duct to house a simulated radiator suitable for a liquid-cooled engine. The duct was expanded to reduce the radiator losses, and the installation of the duct and radiator was made entirely within the wing to reduce form and interference drag. The tests were made using a two-dimensional flow set-up with a full-span duct and radiator" (p. 1).
Date: July 1938
Creator: Harris, Thomas A. & Recant, Isidore G.
Item Type: Refine your search to only Report
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Investigation of Ignition and Combustion Processes of Diesel Engines Operating With Turbulence and Air-Storage Chambers

Description: The flame photographs obtained with combustion-chamber models of engines operating respectively, with turbulence chamber and air-storage chambers or cells, provide an insight into the air and fuel movements that take place before and during combustion in the combustion chamber. The relation between air velocity, start of injection, and time of combustion was determined for the combustion process employing a turbulence chamber.
Date: April 1938
Creator: Petersen, Hans
Item Type: Refine your search to only Report
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Investigations on the Downwash Behind a Tapered Wing With Fuselage and Propeller

Description: "The new downwash measurements behind a tapered wing with parallel center section described in the present report can be brought into good agreement with theoretical calculations if made on the basis of not-rolled-up vortex sheet and allowance is made for the lowering of the sheet. The test values are about 1 degree higher than the "upper limit" established for it, as against approximately 0.5 degrees in the earlier tests behind a rectangular and elliptical wing. The measurements on lateral axe… more
Date: September 1938
Creator: Muttray, H.
Item Type: Refine your search to only Report
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Karakul sheep.

Description: Describes the characteristics of karakul sheep and their importance as a source of wool.
Date: October 1938
Creator: Potts, C. G. & Simmons, V. L. (Victor Leonidas), 1901-
Item Type: Refine your search to only Book
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The knocking characteristics of fuels in relation to maximum permissible performance of aircraft engines

Description: An analysis is presented of the relationship of various engine factors to knock in preignition in an aircraft engine. From this analysis and from the available experimental data, a method of evaluating the knocking characteristics of the fuel in an aircraft-engine cylinder is suggested.
Date: September 14, 1938
Creator: Rothrock, A. M. & Biermann, Arnold E.
Item Type: Refine your search to only Report
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The Lift Distribution of Wings With End Plates

Description: The object of the present report is to ascertain the relationship of the circulation distribution over the wing and of the lift to the height and position of the end plate. The side forces and moments on the end plates were also determined. It is found that moving an end plate of certain length up from the symmetrical position, is followed by a slight increase of the total lift.
Date: April 1938
Creator: Mangler, W.
Item Type: Refine your search to only Report
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Load Tests on a Stiffened Circular Cylindrical Shell

Description: The present report describes tests in which the stress distribution may be determined in a stiffened circular cylindrical shell loaded longitudinally at four symmetrically situated points. As being of particular importance are the cases investigated of groups of bending and arching or convexing forces, respectively. From the stress measurements on the longitudinal stiffeners, the shear stresses and the bulkhead ring stresses in the skin could be evaluated.
Date: May 1938
Creator: Schapitz, E. & Krümling, G.
Item Type: Refine your search to only Report
open access

Longitudinal Stability in Relation to the Use of an Automatic Pilot

Description: "The effect of restraint in pitching introduced by an automatic pilot upon the longitudinal stability of an airplane has been studied. Customary simplifying assumptions have been made in setting down the equations of motion, and the results of computations based on the simplified equations are presented to show the effect of an automatic pilot installed in an airplane of known dimensions and characteristics. The equations developed have been applied by making calculations for a Clark biplane an… more
Date: September 1938
Creator: Klemin, Alexander; Pepper, Perry A. & Wittner, Howard A.
Item Type: Refine your search to only Report
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