National Advisory Committee for Aeronautics (NACA) - 72 Matching Results

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Full-scale wind-tunnel tests of a propeller with the diameter changed by cutting off the blade tips

Description: Tests were conducted in order to determine how the characteristics of a propeller are affected by cutting off the tips. The diameter of a standard 10-foot metal propeller was changed successively to 9 feet 6 inches, 9 feet 0 inches, 8 feet 6 inches, and 8 feet 0 inches. Each propeller thus formed was tested at four pitch settings using an open cockpit fuselage and a D-12 engine. A small loss in propulsive efficiency is indicated. Examples are given showing the application of the results to prac… more
Date: December 10, 1929
Creator: Wood, Donald H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Water pressure distribution on a flying boat hull

Description: This is the third in a series of investigations of the water pressures on seaplane floats and hulls, and completes the present program. It consisted of determining the water pressures and accelerations on a Curtiss H-16 flying boat during landing and taxiing maneuvers in smooth and rough water.
Date: December 4, 1929
Creator: Thompson, F. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Airplane Drag

Description: It has been less well understood that the induced drag (or, better said, the undesired increase in the induced drag as compared with the theoretical minimum calculated by Prandtl) plays a decisive role in the process of taking off and therefore in the requisite engine power. This paper seeks to clarify the induced drag.
Date: December 1929
Creator: Töpfer, Carl
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Balance of Moments and the Static Longitudinal Stability of Airplanes

Description: A nomogram is developed which renders it possible by drawing a few lines, to determine: the location of the center of gravity for zero wing and tail moments; the longitudinal dihedral angle; the tail coefficient F(sub h) iota/F(sub t). Moreover there is no difficulty in determining the magnitude of the restoring moment or of the unstable moment.
Date: December 1929
Creator: Müller, Horst
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculation of the Pressures on Aircraft Engine Bearings

Description: For aircraft engines the three principal operating conditions are idling speed, cruising speed, and diving with the engine stopped. In what follows, we will discuss a method which affords a good idea of the course of pressure for the above mentioned operating conditions. The pressures produced in the driving gear are of three kinds; namely, the pressure due to gases, the pressure due to the inertia of the rotating masses, and the pressure due to the inertia of the reciprocating masses.
Date: December 1929
Creator: Steigenberger, O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Contribution to the Aileron Theory

Description: "In an attempt to treat theoretically the effect of ailerons, difficulty arises because an aileron may begin at any point of the wing. Hence the question arises as to how the transition of the lift distribution proceeds at such a point, since the effect of the aileron (i.e., the moment generated about the longitudinal axis) depends largely on this distribution. In order to answer this question regarding the lift distribution during irregular variations in the angle of attack at first independen… more
Date: December 1929
Creator: Betz, A. & Petersohn, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Some effects of air flow on the penetration and distribution of oil sprays

Description: Tests were made to determine the effects of air flow on the characteristics of fuel sprays from fuel injection valves. Curves and photographs are presented showing the airflow throughout the chamber and the effects of the air flow on the fuel spray characteristics. It was found that the moving air had little effect on the spray penetration except with the 0.006 inch orifice. The moving air did, however, affect the oil particles on the outside of the spray cone. After spray cut-off, the air flow… more
Date: December 1929
Creator: Rothrock, A. M. & Beardsley, E. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wind tunnel pressure distribution tests on a series of biplane wing models Part III: effects of charges in various combinations of stagger, gap, sweepback, and decalage

Description: A concept for the calculation of the vortex lift of sharp-edge delta wings is presented and compared with experimental data. The concept is based on an analogy between the vortex lift and the leading-edge suction associated with the potential flow about the leading edge. This concept, when combined with potential-flow theory modified to include the nonlinearities associated with the exact boundary condition and the loss of the lift component of the leading-edge suction, provides excellent predi… more
Date: December 1929
Creator: Knight, Montgomery & Noyes, Richard W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Water pressure distribution on a twin-float seaplane

Description: This is the second of a series of investigations to determine water pressure distribution on various types of seaplane floats and hulls, and was conducted on a twin-float seaplane. It consisted of measuring water pressures and accelerations on a TS-1 seaplane during numerous landing and taxiing maneuvers at various speeds and angles. The results show that water pressures as great as 10 lbs. per sq. in.may occur at the step in various maneuvers and that pressures of approximately the same magnit… more
Date: December 28, 1928
Creator: Thompson, F. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental and analytical determination of the motion of hydraulically operated valve stems in oil engine injection systems

Description: This research on the pressure variations in the injection system of the N.A.C.A. Spray Photography Equipment and on the effects of these variations on the motion of the timing valve stem was undertaken in connection with the study of fuel injection systems for high-speed oil engines. The methods of analysis of the pressure variations and the general equation for the motion of the spring-loaded stem for the timing valve are applicable to a spring-loaded automatic injection valve, and in general … more
Date: December 26, 1928
Creator: Gelalles, A. G. & Rothrock, A. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Drag and Cooling With Various Forms of Cowling for A "Whirlwind" Radial Air-Cooled Engine - 2

Description: "This report gives the results of the second portion of an investigation in the twenty-foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics, on the cowling and cooling of a "Whirlwind" J-5 radial air-cooled engine. The first portion pertains to tests with a cabin fuselage. This report covers tests with several forms of cowling, including conventional types, individual fairings behind the cylinders, individual hoods over the over the cylinders, and the new N. A. C. A… more
Date: December 17, 1928
Creator: Weick, Fred E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Flow and Force Equations for a Body Revolving in a Fluid

Description: Part I gives a general method for finding the steady-flow velocity relative to a body in plane curvilinear motion, whence the pressure is found by Bernoulli's energy principle. Integration of the pressure supplies basic formulas for the zonal forces and moments on the revolving body. Part II, applying this steady-flow method, finds the velocity and pressure at all points of the flow inside and outside an ellipsoid and some of its limiting forms, and graphs those quantities for the latter forms.… more
Date: December 17, 1928
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tables for pressure of air on coming to rest from various speeds

Description: From Summary: "In Technical Report no. 247 of the National Advisory Committee for Aeronautics theoretical formulas are given from which was computed a table for the pressure of air on coming to rest from various speeds, such as those of aircraft and propeller blades. In that report, the table gave incompressible and adiabatic stop pressures of air for even-speed intervals in miles per hour and for some even-speed intervals in knots per hour. Table II of the present report extends the above-ment… more
Date: December 17, 1928
Creator: Zahm, A. F. & Louden, F. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Aerodynamic Characteristics of Thin Empirical Profiles and Their Application to the Tail Surfaces and Ailerons of Airplanes

Description: From Introduction: "The increasing use of airplane wings equipped with ailerons and the importance of knowing the aerodynamic characteristics of tail units (empennages) provided with movable parts (rudders and elevators) impart some interest to the so-called "empirical profiles." For this purpose we thought best to employ the method proposed by Munk for the approximate theoretical study of thin, slightly curved profiles, assimilable, from an aerodynamic view-point, to their mean camber line."
Date: December 1928
Creator: Toussaint, A. & Carafoli, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Influence of Fuselage on Propeller Design

Description: "In the present paper I shall not consider the problem of the best arrangement of airplane and propeller, but only a simple method for designing a propeller for a given arrangement of airplane parts. The inflow to the propeller and hence the efficiency of the propeller is affected most by the fuselage. The effect of the wings and of the other parts lying in the propeller slip stream is much less and is also more difficult to determine" (p. 1-2).
Date: December 1928
Creator: Troller, Theodor
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Propeller Problems

Description: This report tries to give a comprehensive survey of the most important propeller problems such as the shape of propellers and the effect of atmospheric conditions on propeller performance.
Date: December 1928
Creator: Betz, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The torsional strength of wings

Description: This report describes a simple method for calculating the position of the elastic axis of a wing structure having any number of spars. It is shown that strong drag bracing near the top and bottom of a wing greatly increases the torsional strength. An analytical procedure for finding the contribution of the drag bracing to the torsional strength and stiffness is described, based upon the principle of least work, and involving only one unknown quantity. A coefficient for comparing the torsional r… more
Date: December 1928
Creator: Burgess, C. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Comparative Performance of Roots Type Aircraft Engine Superchargers as Affected by Change in Impeller Speed and Displacement

Description: "This report presents the results of tests made on three sizes of roots type aircraft engine superchargers. The impeller contours and diameters of these machines were the same, but the length were 11, 8 1/4, and 4 inches, giving displacements of 0.509, 0.382, and 0.185 cubic foot per impeller revolution. The information obtained serves as a basis for the examination of the individual effects of impeller speed and displacement on performance and of the comparative performance when speed and disp… more
Date: December 23, 1927
Creator: Ware, Marsden & Wilson, Ernest E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Water-pressure distribution on seaplane float

Description: The investigation presented in this report was conducted for the purpose of determining the distribution and magnitude of water pressures likely to be experienced on seaplane hulls in service. It consisted of the development and construction of apparatus for recording water pressures lasting one one-hundredth second or longer and of flight tests to determine the water pressures on a UO-1 seaplane float under various conditions of taxiing, taking off, and landing. The apparatus developed was fou… more
Date: December 22, 1927
Creator: Thompson, F. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculating Thrust Distribution and Efficiency of Air Propellers

Description: I am now proposing a method for the preliminary approximate calculation of the thrust distribution and efficiency of air propellers under any operating conditions. Our task becomes the following, namely, to determine the speed relations and the forces developed on a section with a given direction and velocity of the air current, a problem which can be solved with the aid of the momentum theory.
Date: December 1927
Creator: Bienen, Theodor
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Characteristics of the N.A.C.A 97, Clark Y, and N.A.C.A. M6 Airfoils with Particular Reference to the Angle of Attack

Description: Report examining the aerodynamic characteristics of three airfoil sections as determined in the variable density wind tunnel. Particular attention is given to the relation of the characteristics to the angle of attack and their use in airplane design.
Date: December 1927
Creator: Higgins, George J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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