UNT Libraries Government Documents Department - 124 Matching Results

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The Calculation of Lateral Stability With Free Controls

Description: The discussion of the structural methods for obtaining lateral stability discloses the remarkable influence of the constant fuselage and wing proportions to the yawing moments. For the effectiveness of modifications in vertical tail surfaces and tail length, these quotas - little observed heretofore, in this connection - are decisive. This also applies to the amount of dihedral of the wing with regard to the roll stability of the complete wing already existing without angle of the dihedral.
Date: April 1934
Creator: Mathias, Gotthold
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The calculation of take-off run

Description: From Summary: "A comparatively simple method of calculating length of take-off run is developed from the assumption of a linear variation in net accelerating force with air speed and it is shown that the error involved is negligible. Detailed instructions are given for application of the formula and for the calculation of all factors involved."
Date: January 1934
Creator: Diehl, Walter S.
open access

A comparison of fuel sprays from several types of injection nozzles

Description: This report presents the tests results of a series of tests made of the sprays from 14 fuel injection nozzles of 9 different types, the sprays being injected into air at atmospheric density and at 6 and 14 times atmospheric density. High-speed spark photographs of the sprays from each nozzle at each air density were taken at the rate of 2,000 per second, and from them were obtained the dimensions of the sprays and the rates of spray-tip penetration. The sprays were also injected against plastic… more
Date: December 4, 1934
Creator: Lee, Dana W.
open access

A comparison of several methods of measuring ignition lag in a compression-ignition engine

Description: "The ignition lag of a fuel oil in the combustion chamber of a high speed compression-ignition engine was measured by three different methods. The start of injection of the fuel as observed with a Stoborama was taken as the start of the period of ignition lag in all cases. The end of the period of ignition lag was determined by observation of the appearance of incandescence in the combustion chamber, by inspection of a pressure-time card for evidence of pressure rise, and by analysis of the ind… more
Date: January 1934
Creator: Spanogle, J. A.
open access

A complete tank test of a flying-boat hull with a pointed step - N.A.C.A. Model No. 22

Description: "The results of a complete tank test of a model of a flying-boat hull of unconventional form, having a deep pointed step, are presented in this note. The advantage of the pointed-step type over the usual forms of flying-boat hulls with respect to resistance at high speeds is pointed out. A take-off example using the data from these tests is worked out, and the results are compared with those of an example in which the test data for a hull of the type in general use in the United States are appl… more
Date: February 1934
Creator: Shoemaker, James M.
open access

A complete tank test of the hull of the Sikorsky S-40 flying boat - American Clipper Class

Description: The results of a complete test in the N.A.C.A. tank on a model of the hull of Sikorsky S-40 flying boat ('American Clipper') are reported. The test data are given in tables and curves. From these data non-dimensional coefficients are derived for use in take-off calculations and the take-off time and run for the S-40 are computed. The computed take-off time was obtained by the Sikorsky Aviation Corporation in performance tests of the actual craft.
Date: December 1934
Creator: Dawson, John R.
open access

Complete tank tests of two flying-boat hulls with pointed steps - N.A.C.A. Models 22-A and 35

Description: "This note presents the results of complete tank test of N.A.C.A. Models 22-A and 35, two flying-boat hulls of the deep pointed-step type with low dead rise. Model 22-A is a form derived by modification of Model 22, the test results of which are given in N.A.C.A. Technical Note No. 488. Model 35 is a form of the same type but has a higher length-beam ratio than either Model 22 or 22-A. Take-off examples are worked out using data from these tests and a previous test of a conventional model appli… more
Date: September 1934
Creator: Shoemaker, James M. & Bell, Joe W.
open access

Computation of the two-dimensional flow in a laminar boundary layer

Description: A comparison is made of the boundary-layer flow computed by the approximate method developed by K. Pohlhausen with the exact solutions which have been published for several special cases. A modification of Pohlhausen's method has been developed which extends the range of application at the expense of some decrease in the accuracy of the approximations.
Date: May 1934
Creator: Dryden, Hugh L.
open access

Contribution to the Mutual Interference of Wing and Propeller

Description: "The change of induced wing drag due to the field of flow of the propeller was analyzed quantitatively. The field of flow of the propeller is represented by a uniform distribution of sinks over the propeller disk area, whose strength is determined by the increase in speed in the slipstream. The superposition of this sink flow on the basic flow reproduces the actual field of flow outside of the slipstream with close approximation" (p. 1).
Date: September 1934
Creator: Wieselsberger, C.
open access

Conversion of Energy in Cross-Sectional Divergences Under Different Conditions of Inflow

Description: "This investigation treats the conversion of energy in conically divergent channels with constant opening ratio and half included angle of from 2.6 to 90 degrees, the velocity distribution in the entrance section being varied from rectangular distribution to fully developed turbulence by changing the length of the approach. The energy conversion is not completed in the exit section of the diffuser; complete conversion requires a discharge length which depends upon the included angle and the vel… more
Date: March 1934
Creator: Peters, H.
open access

Cooling characteristics of a 2-row radial engine

Description: This report presents the results of cooling tests conducted on a calibrated GR-1535 Pratt and Whitney Wasp, Jr. Engine installed in a Vought X04U-2 airplane. The tests were made in the NACA full-scale tunnel at air speeds from 70 to 120 miles per hour, at engine speeds from 1,500 to 2,600 r.p.m., and at manifold pressures from 19 to 33 inches of mercury absolute. A Smith controllable propeller was used to facilitate obtaining the different combinations of engine speed, power, and manifold press… more
Date: December 4, 1934
Creator: Schey, Oscar W. & Rollin, Vern G.
open access

A description and test results of a spark-ignition and a compression-ignition 2-stroke-cycle engine

Description: This report presents performance results of air cooled and water-cooled engines. The results obtained were sufficiently promising to warrant further investigation with fuel injection and spark ignition, with the same arrangement of inlet ports and exhaust valves at the bottom of the cylinder and the exhaust gases discharged through two poppet valves in the cylinder head. The displacement of the engine was 118 cubic inches. Optimum performance was obtained with the inlet air directed into the cy… more
Date: May 14, 1934
Creator: Spanogle, J. A. & Whitney, E. G.
open access

The drag of airplane wheels, wheel fairings, and landing gears - 1

Description: This report presents the results of tests made in the 7-by 10-foot wind tunnel and in the 20-foot tunnel of the National Advisory Committee for Aeronautics to determine the drag of a number of airplane wheels, wheel fairings, and landing gears designed or selected for an airplane of 3,000 pounds gross weight. All tests were made on full-size models; those in the 7-by 10-foot tunnel were made at air speeds up to 80 miles per hour and those in the 20-foot tunnel were made at air speeds up to 100 … more
Date: February 9, 1934
Creator: Herrnstein, William H., Jr. & Biermann, David
open access

The drag of airplane wheels, wheel fairings, and landing gears 2: nonretractable and partly retractable landing gears

Description: This is the second report giving the results obtained in the NACA 20-foot wind tunnel on the drag due to landing gears. The present report gives the results of tests of nonretractable and partly retractable landing gears intended for heavier low-wing monoplanes of the transport and bomber type.
Date: June 21, 1934
Creator: Biermann, David & Herrnstein, William H., Jr.
open access

The drag of airplane wheels, wheel fairings, and landing gears - 3

Description: The tests reported in this report conclude the investigation of landing-gear drag that has been carried out in the NACA 20-foot wind tunnel. They supplement earlier tests (reported in Technical Report No. 485) made with full-scale dummy wheels, wheel fairings, and landing gears intended for airplanes of 3,000 pounds gross weight and include tests of tail wheels and tail skids.
Date: November 21, 1934
Creator: Herrnstein, William H., Jr. & Biermann, David
open access

The effect of baffles on the temperature distribution and heat-transfer coefficients of finned cylinders

Description: This report presents the results of an investigation to determine the effect of baffles on the temperature distribution and the heat-transfer coefficient of finned cylinders. The tests were conducted in a 30-inch wind tunnel on electrically heated cylinders with fins of 0.25 and 0.31 inch pitch. The results of these tests showed that the use of integral baffles gave a reduction of 31.9 percent in the rear wall temperatures and an increase of 54.2 percent in the heat transfer coefficient as comp… more
Date: September 26, 1934
Creator: Schey, Oscar W. & Rollin, Vern G.
open access

Effect of Combustion-Chamber Shape on the Performance of a Prechamber Compression-Ignition Engine

Description: "The effect on engine performance of variations in the shape of the prechamber, the shape and direction of the connecting passage, the chamber volume using a tangential passage, the injection system, and the direction of the fuel spray in the chamber was investigated using a 5 by 7 inch single-cylinder compression-ignition engine. The results show that the performance of this engine can be considerably improved by selecting the best combination of variables and incorporating them in a single de… more
Date: December 1934
Creator: Moore, C. S. & Collins, J. H., Jr.
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Effect of Fuselage and Engine Nacelles on Some Aerodynamic Properties of an Airplane Wing

Description: "With the aid of the method of J. Lotz, the writer undertook to solve theoretically the lift distribution along the span of an airplane wing, when the outline of the wing is uneven. This problem arises in the case of a mid-wing monoplane with embedded engine nacelles. The fuselage and the nacelles were considered as aerodynamically profiled, that is, as lift-producing parts. The task was therefore to determine not only the disturbance caused by the fuselage and nacelles, but also their share in… more
Date: February 1934
Creator: Vladea, Joan
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Effect of moderate air flow on the distribution of fuel sprays after injection cut-off

Description: "High-speed motion pictures were taken of fuel sprays with the NACA spray-photographic apparatus to study the distribution of the liquid fuel from the instant of injection cut-off until about 0.05 second later. The fuel was injected into a glass-walled chamber in which the air density was varied from 1 to 13 times atmospheric air density (0.0765 to 0.99 pound per cubic foot) and in which the air was at room temperature. The air in the chamber was set in motion by means of a fan, and was directe… more
Date: February 14, 1934
Creator: Rothrock, A. M. & Spencer, R. C.
open access

Effect of Retractable-Spoiler Location on Rolling- and Yawing-Moment Coefficients

Description: "In this report are presented the results of wind-tunnel tests of retractable spoilers on the upper surface of a Clark Y wing, which have been made as part of an investigation of lateral control devices being conducted by the National Advisory Committee for Aeronautics. Spoilers with chords up to 15.0 percent of the wing chord were tested in several locations on a plain rectangular wing and in two locations on the same wing equipped with a 20.0 percent chord split flap down 60 degrees. Charts a… more
Date: July 1934
Creator: Shortal, J. A.
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The Effect of Spray Strips on the Take-Off Performance of a Model of a Flying-Boat Hull

Description: "The effect on the take-off performance of a model of the hull of a typical flying boat, Navy PH-1, of fitting spray strips of four different widths, each at three different angles, was determined by model tests in the NACA Tank. Spray strips of widths up to 3 percent of the beam improve the general performance at speeds near the hump and reduce the spray thrown. A downward angle of 30 degrees to 45 degrees in the neighborhood of the step seems most favorable for the reduction of the spray" (p.… more
Date: June 15, 1934
Creator: Truscott, Starr
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