National Advisory Committee for Aeronautics (NACA) - 1,346 Matching Results

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Tank tests of a model of a flying-boat hull having a longitudinally concave planing bottom

Description: "The NACA model 11-B, which has a longitudinally concave planing bottom forward of the step, was tested over a wide range of loading. The results of the tests are presented as curves of resistance and trimming moment plotted against speed for various trim angles and as curves of resistance coefficient at best trim angle, and trimming-moment coefficient. The characteristics of the form at the optimum trim are compared with those of NACA model 11-C which has the same form with the exception of a … more
Date: November 1935
Creator: Parkinson, J. B.
Partner: UNT Libraries Government Documents Department
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Tank tests of a model of a flying-boat hull with a fluted bottom

Description: A 1/5-scale model of a flying-boat hull having flutes in the bottom both forward and aft of the step (NACA model 19) was tested to determine its water performance. The model was also tested after the successive removal of the flutes on the afterbody and forebody. The results from these tests are compared with those from tests of a model of the hull of the Navy PN-8 flying boat and it is concluded that the fluted-bottom model and its modifications are inferior to the model of the PN-8.
Date: March 1935
Creator: Dawson, John R.
Partner: UNT Libraries Government Documents Department
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Tank tests of a model of one hull of the Savoia S-55-X flying boat - N.A.C.A. Model 46

Description: A model of one of the twin hulls of the Italian Savoia S-55-X flying boat (N.A.C.A. Model 46) was tested in the N.A.C.A. tank according to the general method. The data obtained from these tests cover a broad range of speeds, loads, and trims and are given in nondimensional form to facilitate their use in applying this form of hull to any other flying boat or comparing it's performance with the performance of any other hulls. The results show that the resistance characteristics at best trim of t… more
Date: February 1938
Creator: Allison, John M.
Partner: UNT Libraries Government Documents Department
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Tank Tests of a Model of the NC Flying-Boat Hull - N.A.C.A. Model 44

Description: "A 1/7.06 full-size model of the NC-type hull was tested in the N.A.C.A. tank by both the general method and the specific or free-to-trim method. The results of the tests are given in curves plotted as non dimensional coefficients and are compared with the test results of N.A.C.A. model 11-A. The NC model (N.A.C.A. model 44) shows higher resistance than model 11-A at hump speed but lower resistance at high speeds. Model 44 has a higher best trim angle at the jump and a lower maximum positive tr… more
Date: May 1936
Creator: Bell, Joe W.
Partner: UNT Libraries Government Documents Department
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Tank tests of auxiliary vanes as a substitute for planing area

Description: The results of towing tests made on two models at the request of the Bureau of Aeronautics, Navy Department, are presented. The first model represents the hull of the U.S. Navy PN-8 flying boat, in which the sponsors of the original hull are removed and auxiliary lifting vanes are fitted at the chines immediately forward of the main step. The tests showed that the altered form gave a large increase in hump resistance and a very undesirable spray formation through a large part of the speed range. more
Date: February 1934
Creator: Parkinson, John B.
Partner: UNT Libraries Government Documents Department
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Tank Tests of Flat and V-Bottom Planning Surfaces

Description: "Four planing surfaces, all having beams of 16 inches and lengths of 60 inches but varying in dead rise by 10 degrees increments from 0 degrees to 30 degrees, were tested in the N.A.C.A. tank. The results cover a wide range of speed, loads, and trim angles, and are applicable to a variety of problems encountered in the design of seaplanes. The data are analyzed to determine the characteristics of each surface at the trim angle giving minimum resistance for all the speed and loads tested. A plan… more
Date: November 1934
Creator: Shoemaker, James M.
Partner: UNT Libraries Government Documents Department
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Tank tests of model 11-G flying-boat hull

Description: "The NACA model 11-G flying-boat hull, a modification of NACA model 11-A was tested over a range of loadings. The planing bottom of model 11-G has a variable-radius flare, or concavity, at the chines in contrast to the straight V planing bottom of model 11-A. The results are given as curves of resistance and trimming moment plotted against speed for various angles of trim" (p. 1).
Date: June 1935
Creator: Parkinson, J. B.
Partner: UNT Libraries Government Documents Department
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Tank Tests of Model 36 Flying Boat Hull

Description: "N.A.C.A. Model 36, a hull form with parallel middle body for half the length of the forebody and designed particularly for use with stub wings, was tested according to the general fixed-trim method over the range of practical loads, trims, and speeds. It was also tested free to trim with the center of gravity at two different positions. The results are given in the form of nondimensional coefficients. The resistance at the hump was exceptionally low but, at high planing speeds, afterbody inter… more
Date: March 1938
Creator: Allison, John M.
Partner: UNT Libraries Government Documents Department
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Tank tests of models of floats for single-float seaplanes - First series

Description: "Large models of the Mark V and Mark VI floats used for single float seaplanes (National Advisory Committee for Aeronautics (NACA) models 41-A and 41-B, respectively) were tested in the NACA tank to provide general test data for typical single floats and a basis for possible improvements of their form. The resistance of model 41-B was greater than that of model 41-A, either when free to trim or at the best trim angle for each. The resistance of model 35-B (a pointed step hull tested free to tri… more
Date: April 1936
Creator: Parkinson, J. B.
Partner: UNT Libraries Government Documents Department
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Tank tests of models of flying boat hulls having longitudinal steps

Description: Four models with longitudinal steps on the forebody were developed by modification of a model of a conventional hull and were tested in the National Advisory Committee for Aeronautics (NACA) tank. Models with longitudinal steps were found to have smaller resistance at high speed and greater resistance at low speed than the parent model that had the same afterbody but a conventional V-section forebody. The models with a single longitudinal step had better performance at hump speed and as low hig… more
Date: July 1936
Creator: Allison, John M. & Ward, Kenneth E.
Partner: UNT Libraries Government Documents Department
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Tank tests of NACA model 40 series of hulls for small flying boats and amphibians

Description: From Summary: "The NACA model 40 series of flying-boat hull models consists of 2 forebodies and 3 afterbodies combined to provide several forms suitable for use in small marine aircraft. One forebody is the usual form with hollow bow sections and the other has a bottom surface that is completely developable from bow to step. The afterbodies include a short pointed afterbody with an extension for the tail surfaces, a long afterbody similar to that of a seaplane float but long enough to carry the… more
Date: June 19, 1935
Creator: Parkinson, John B. & Dawson, John R.
Partner: UNT Libraries Government Documents Department
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Tank Tests of the Effect of Rivet Heads, etc., on the Water Performance of a Seaplane Float, Special Report

Description: "A 1/3.5 full-size model of the Mark V float of the Bureau of Aeronautics, Navy Department, was tested in the NACA tank both with smooth painted bottom surfaces and with roundhead rivets, plate laps, and keel plates fitted to simulate the actual bottom of a metal float. The augmentation in water resistance due to the added roughness was found to be from 10-12% at the hum speed and from 12-14% at high speeds. The effect of the roughness of the afterbody was found to be negligible except at high … more
Date: June 4, 1936
Creator: Parkinson, J. B. & Robertson, J. B., Jr.
Partner: UNT Libraries Government Documents Department
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Tank tests of three models of flying-boat hulls of the pointed-step type with different angles of dead rise - NACA model 35 series

Description: From Summary: "The results of tank tests of three models of flying-boat hulls of the pointed-step type with different angles of dead rise are given in charts and are compared with results from tests of more conventional hulls. Increasing the angle of dead rise from 15 to 25 degrees: had little effect on the hump resistance; increased the resistance throughout the planning range; increased the best trim angle; reduced the maximum positive trimming moment required to obtain best trim angle; and h… more
Date: January 1936
Creator: Dawson, John R.
Partner: UNT Libraries Government Documents Department
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Tank Tests of Two Floats for High-Speed Seaplanes

Description: "At the request of the Bureau of Aeronautics, Navy Department, a study of the design of floats especially suitable for use on high-speed seaplanes was undertaken in the N.A.C.A. tank. This note give the results obtained in tests of one-quarter full-size models of two floats for high-speed seaplanes. One was a float similar to that used on the Macchi high-speed seaplane which competed in the 1926 Schneider Trophy races, and the other a float designed at the N.A.C.A. tank in an attempt to improve… more
Date: November 1933
Creator: Bell, Joe W.
Partner: UNT Libraries Government Documents Department
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Tank tests of two models of flying-boat hulls to determine the effect of ventilating the step

Description: From Summary: "The results of tests made in the N.A.C.A. tank on two models of flying-boat hulls to determine the effect of ventilating the step are given graphically. The step of N.A.C.A. model 11-C was ventilated in several different ways and it was found that the resistance of the normal form is not appreciably affected by artificial ventilation in any of the forms tried. Further tests made with the depth of the step of model 11-C reduced likewise show no appreciable effect on the resistance… more
Date: February 1937
Creator: Dawson, John R.
Partner: UNT Libraries Government Documents Department
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Tank Tests to Determine the Effects of the Chine Flare of a Flying-Boat Hull N.A.C.A. Model Series 62 and 69

Description: Note presenting testing of twenty-two models of flying-boat hulls for the purpose of determining the effects on water resistance and spray of 13 variations in the transverse section of the bottom of the forebody and of three variations in the form of the afterbody. Generally, the effect of chine flare on the resistance was small, although the resistance of force with chine flare was generally less than the resistance of the form without chine flare.
Date: August 1939
Creator: Bell, Joe W. & Olson, Roland E.
Partner: UNT Libraries Government Documents Department
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Tank Tests to Show the Effect Rivet Heads on the Water Performance of a Seaplane-Float

Description: "A 1/3.5 full-sized model of a seaplane float constructed from lines supplied by the Bureau of Aeronautics, Navy Department, was tested first with smooth painted bottom surfaces and then with round-head rivets, plate laps, and keel plates fitted to simulate the actual bottom of a metal float. A percentage increase in water resistance caused by the added roughness was found to be from 5 to 20 percent at the hump speed and from 15 to 40 percent at high speeds. The effect of the roughness of the a… more
Date: July 1938
Creator: Parkinson, J. B.
Partner: UNT Libraries Government Documents Department
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Tanks test of a model of the hull of the Navy PB-1 flying boat - N.A.C.A. Model 52

Description: A model of the hull of the Navy PB-1 flying boat was tested in the N.A.C.A. tank as part of a program intended to provide information regarding the water performance of hulls of flying boats of earlier design for which hydrodynamic data have heretofore been unavailable. Tests were made according to the general method over the range of practical loadings with the model both fixed in trim and free to trim. A free-to-trim test according to the specific method was also made for the design load and … more
Date: August 1936
Creator: Allison, John M.
Partner: UNT Libraries Government Documents Department
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Tapered Wings, Tip Stalling, and Preliminary Results From Tests of the Stall-Control Flap

Description: Report presenting a consideration of the general problem of stalling as affecting the safety of airplanes. The increased difficulties associated with modern efficient wings, particularly highly tapered wings and high-life devices, are discussed and means are considered for avoiding these difficulties.
Date: November 1937
Creator: Jacobs, Eastman N.
Partner: UNT Libraries Government Documents Department
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Temperature coefficient of the modulus of rigidity of aircraft instrument diaphragm and spring materials

Description: Experimental data are presented on the variation of the modulus of rigidity in the temperature range -20 to +50 degrees C. of a number of metals which are of possible use for elastic elements for aircraft and other instruments. The methods of the torsional pendulum was used to determine the modulus of rigidity and its temperature coefficient for aluminum, duralumin, monel metal, brass, phosphor bronze, coin silver, nickel silver, three high carbon steels, and three alloy steels. It was observed… more
Date: March 7, 1930
Creator: Brombacher, W. G. & Melton, E. R.
Partner: UNT Libraries Government Documents Department
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Temperature-Indicating Paints

Description: This report is an attempt at a new method of coating the surface of the cylinder with materials that undergo chemical change at definite temperatures as indicated by a change in color. In this way it was hoped that the substance itself would indicate directly the position of its isotherms, which in measurements with thermocouples requires a tedious amount of labor.
Date: August 1939
Creator: Penzig, F.
Partner: UNT Libraries Government Documents Department
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Tensile Elastic Properties of 18:8 Chromium-Nickel Steel as Affected by Plastic Deformation

Description: "The relationship between stress and strain, and between stress and permanent set, for 18:8 alloy as affected by prior plastic deformation is discussed. Hysteresis and creep and their effects on the stress-strain and stress-set curves are also considered, as well as the influence of duration of the rest interval after cold work and the influence of plastic deformation on proof stresses, on the modulus of elasticity at zero stress, and on the curvature of the stress-strain line. A constant (c su… more
Date: November 22, 1938
Creator: McAdam, D. J., Jr. & Mebs, R. W.
Partner: UNT Libraries Government Documents Department
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Tension fields in originally curved, thin sheets during shearing stresses

Description: The analysis of the stresses in the sheet and stiffeners is predicated upon the direction of the wrinkles, particularly the tensile stresses (principal stresses). This analysis and the calculation of stresses after buckling form the subject of the present article. It includes: 1) metal cylinders with closely spaced longitudinal stiffeners; 2) metal cylinders with closely spaced transverse rings.
Date: August 1935
Creator: Wagner, H. & Ballerstedt, W.
Partner: UNT Libraries Government Documents Department
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