UNT Libraries Government Documents Department - 34 Matching Results

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Principal Effects of Axial Load on Moment-Distribution Analysis of Rigid Structures

Description: "This thesis presents the method of moment distribution modified to include the effect of axial load upon the bending moments. This modification makes it possible to analyze accurately complex structures, such as rigid fuselage trusses, that heretofore had to be analyzed by approximate formulas and empirical rules. The method is simple enough to be practicable even for complex structures, and it gives a means of analysis for continuous beams that is simpler than the extended three-moment equati… more
Date: July 1935
Creator: James, Benjamin Wylie
Item Type: Refine your search to only Report
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Calculations of the Effect of Wing Twist on the Air Forces Acting on a Monoplane Wing

Description: "A method is presented for calculating the aerodynamic forces on a moncylane wing, taking into account the elastic twisting of the wing due to these forces. The lift distribution along the span is calculated by the formulas of Amstutz as a function of the geometrical characteristics of the wing and of the twist at stations 60 and 90 percent of the semispan. The twist for a given lift distribution is calculated by means of influence lines" (p. 1).
Date: March 1935
Creator: Dätwyler, G.
Item Type: Refine your search to only Report
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Wind-tunnel tests of a wing with a trailing-edge auxiliary airfoil used as a flap

Description: "This report gives the characteristics of a wing with an auxiliary airfoil mounted near its trailing edge and used as a flap. The tests were made with a 10 by 60 inch Clark Y main airfoil and an NACA 0012 flap having a chord equal to 15 percent of the main wing chord. The axis of the flap in all cases was on the flap chord and 20 percent back from its leading edge. The optimum location of the flap axis relative to the main wing for maximum lift was found to be 1.25 percent of the main wing chor… more
Date: April 1935
Creator: Noyes, Richard W.
Item Type: Refine your search to only Report
open access

Development of the N.A.C.A. Slot-Lip Aileron

Description: "An investigation of the undesirable delayed action, or lag, of the spoiler-type lateral control device led to the development of the NACA slot-lip aileron. The tests were made in the 7- by 10-foot wind tunnel with a 4- by 8-foot wing hinged at the tunnel jet boundary and restrained in roll by elastic cords. Time histories were taken of the motion of the control device under test and of the resulting wing motion" (p. 1).
Date: November 1935
Creator: Weick, Fred E. & Shortal, Joseph A.
Item Type: Refine your search to only Report
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Flight tests of a balanced split flap with particular reference to rapid operation

Description: The flight path of a small parasol monoplane equipped with a special type of balanced split flap was determined for a series of glides during which the time taken to deflect or retract the flap was varied from 1 to 15 seconds in order to study the effect of the time taken to complete a flap movement on the motion of an airplane between the start of a flap movement and the attainment of steady flight with the new flap setting. For flap movements accompanied by a change of lift characteristics, a… more
Date: December 1935
Creator: Soulé, H. A.
Item Type: Refine your search to only Report
open access

Drag of Prestone and Oil Radiators on the YO-31A Airplane

Description: "At the request of the Army Air Corps tests were conducted on a mock-up of the YO-31A airplane to determine the drag of the prestone and oil radiators. The drag of the airplane was determined with both radiators exposed on the lower surface of the fuselage; with each radiator exposed; and with no radiators. The results show that at 120 m.p.h the oil radiator accounted for 2.8 percent of the drag of the complete airplane; the prestone radiator 8.3 percent; and both radiators together, 11.8 perce… more
Date: December 1935
Creator: DeFrance, S. J.
Item Type: Refine your search to only Report
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Method of Testing Oxygen Regulators

Description: Oxygen regulators are used in aircraft to regulate automatically the flow of oxygen to the pilot from a cylinder at pressures ranging up to 150 atmospheres. The instruments are adjusted to open at an altitude of about 15,000 ft. and thereafter to deliver oxygen at a rate which increases with the altitude. The instruments are tested to determine the rate of flow of oxygen delivered at various altitudes and to detect any mechanical defects which may exist.
Date: June 1935
Creator: Sontag, Harcourt & Borlik, E. L.
Item Type: Refine your search to only Report
open access

The Effect of Depth of Step on the Water Performance of a Flying-Boat Hull Model N.A.C.A. Model 11-C

Description: "NACA model 11-C was tested with four different depths of step to obtain information as to the effect of the depth of step on the water performance. The depths of step were selected to cover the practicable range of depths and in each case the included angle between the forebody and afterbody keels was kept the same 6-1/2 degrees. Small depths of step were found to give lower resistance at speeds below and at the hump speed of the model and greater depths of step lower resistance at high speeds… more
Date: July 1935
Creator: Bell, Joe W.
Item Type: Refine your search to only Report
open access

A preliminary determination of normal accelerations on racing airplanes

Description: "Rules and methods for insuring safe structural strength of racing airplanes used in the major air meets in this country have recently been considered. Acceleration records made in racing airplanes during actual air races were therefore considered desirable, and the NACA undertook the measurement of acceleration of loads on airplanes during all conditions of flight. Accelerations were measured on four airplanes at the Miami All-American Races in January 1934 and January 1935" (p. 1).
Date: August 1935
Creator: Scudder, N. F. & Kirschbaum, H. W.
Item Type: Refine your search to only Report
open access

A general tank test of NACA model 11-C flying-boat hull, including the effect of changing the plan form of the step

Description: The results of a general tank test model 11-C, a conventional pointed afterbody type of flying-boat hull, are given in tables and curves. These results are compared with the results of tests on model 11-A, from which model 11-C was derived, and it is found that the resistance of model 11-C is somewhat greater. The effect of changing the plan form of the step on model 11-C is shown from the results of tests made with three swallow-tail and three pointed steps formed by altering the original step… more
Date: August 1935
Creator: Dawson, John R.
Item Type: Refine your search to only Report
open access

A deflection formula for single-span beams of constant section subjected to combined axial and transverse loads

Description: In this paper there is presented a deflection formula for single-span beams of constant section subjected to combined axial and transverse loads of the types commonly encountered in airplane design. The form of the equation is obtainable by dimensional analysis. Tables and curves of the non dimensional coefficients are appended to facilitate the use of the formula. The equation is applied to the determination of the spring constant of a beam. Tables and curves are presented to show the variatio… more
Date: September 1935
Creator: Burke, Walter F.
Item Type: Refine your search to only Report
open access

The Effect of the Angle of Afterbody Keel on the Water Performance of a Flying-Boat Hull Model

Description: NACA model 11-C was tested according to the general method with the angle of afterbody keel set at five different angles from 2-1/2 degrees to 9 degrees, but without changing other features of the hull. The results of the tests are expressed in curves of test data and of non-dimensional coefficients. At the depth of step used in the tests, 3.3 percent beam, the smaller angles of afterbody keel give greater load-resistance ratios at the hump speed and smaller at high speed than the larger angles… more
Date: September 1935
Creator: Allison, John M.
Item Type: Refine your search to only Report
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The Initial Torsional Stiffness of Shells With Interior Webs

Description: "A method of calculating the stresses and torsional stiffness of thin shells with interior webs is summarized. Comparisons between experimental and calculated results are given for 3 duralumin beams, 5 stainless steel beams and 2 duralumin wings. It is concluded that if the theoretical stiffness is multiplied by a correction factor of 0.9, experimental values may be expected to check calculated values within about 10 percent" (p. 1).
Date: September 1935
Creator: Kuhn, Paul
Item Type: Refine your search to only Report
open access

The Compressibility Burble

Description: "Simultaneous air-flow photographs and pressure-distribution measurements have been made of the NACA 4412 airfoil at high speeds in order to determine the physical nature of the compressibility bubble. The flow photographs were obtained by the Schlieren method and the pressures were simultaneously measured for 54 stations on the 5-inch-chord wing by means of a multiple-tube photographic manometer. Pressure-measurement results and typical Schlieren photographs are presented" (p. 1).
Date: October 1935
Creator: Stack, John
Item Type: Refine your search to only Report
open access

Strength Tests of Thin-Walled Duralumin Cylinders in Combined Transverse Shear and Bending

Description: "This report is the fourth of a series presenting the results of strength tests on thin-walled cylinders and truncated cones of circular and elliptic section; it includes the results on 100 thin-walled Duralumin cylinders of circular section with ends clamped to rigid bulkheads. The tests show that as the ratio of moment to shear varies from small to large values the failure changes from a shear to a bending type. In the report a chart is presented that shows the corresponding changes in streng… more
Date: April 1935
Creator: Lundquist, Eugene E.
Item Type: Refine your search to only Report
open access

The Aerodynamic Drag of Flying-Boat Hull Model as Measured in the NACA 20-Foot Wind Tunnel - 1

Description: "The main purpose of this investigation is to make available to the designer useful information with regard to the aerodynamic drag of various types of flying-boat hull models. The present report is the first in a series covering investigation in this field. Through close cooperation between hydrodynamics and aerodynamics divisions it is hoped that results leading to improvements in hull design obtained" (p. 1).
Date: April 1935
Creator: Hartman, Edwin P.
Item Type: Refine your search to only Report
open access

Spinning Characteristics of Wings 2: Rectangular Clark Y Biplane Cellule: 25 Percent Stagger; 0 Degree Decalage; Gap/Chord 1.0

Description: General methods of theoretical analysis of airplane spinning characteristics have been available for some time. Some of these methods of analysis might be used by designers to predict the spinning characteristics of proposed airplane designs if the necessary aerodynamic data were known. The present investigation, to determine the spinning characteristics of wings, is planned to include variations in airfoil sections, plan forms, and tip shapes of monoplane wings and variations in stagger, gap, … more
Date: April 1935
Creator: Bamber, M. J.
Item Type: Refine your search to only Report
open access

Strength tests of thin-walled duralumin cylinders of elliptic section

Description: This report is the fifth of a series presenting the results of strength tests of thin-walled cylinders and truncated cones of circular and elliptic section; it includes the results obtained from torsion tests on 30 cylinders, pure bending tests on 30 cylinders, and combined transverse shear and bending tests on 60 cylinders. All the cylinders tested were elliptic section with the ends clamped to rigid bulkheads. In the pure bending and combined transverse shear and bending tests the loads were … more
Date: May 1935
Creator: Lundquist, Eugene E. & Burke, Walter F.
Item Type: Refine your search to only Report
open access

Wind-tunnel tests of a cyclogiro rotor

Description: During an extensive study of all types of rotating wings, the NACA examined the cyclogiro rotor and made an aerodynamic analysis of that system (reference 1). The examination disclosed that such a machine had sufficient promise to justify an experimental investigation; a model with a diameter and span of 8 feet was therefore constructed and tested in the 20-foot wind tunnel during 1934. The experimental work included tests of the effect of the motion upon the rotor forces during the static-lift… more
Date: May 1935
Creator: Wheatley, John B. & Windler, Ray
Item Type: Refine your search to only Report
open access

Analysis of a Strut With a Single Elastic Support in the Span, With Applications to the Design of Airplane Jury-Strut Systems

Description: Report presenting an analysis of a wing brace with a small auxiliary strut, which is attached to the wing spar at the upper end. The design is quite effective but has some difficult analysis problems. The report is broken into two parts; one is a theoretical investigation and one is an experimental investigation.
Date: May 1935
Creator: Schwartz, A. Murray & Bogert, Reid
Item Type: Refine your search to only Report
open access

Bending Stresses Due to Torsion in Cantilever Box Beams

Description: "The paper beings with a brief discussion on the origin of the bending stresses in cantilever box beams under torsion. A critical survey of existing theory is followed by a summary of design formulas; this summary is based on the most complete solution published but omits all refinements considered unnecessary at the present state of development. Strain-gage tests made by NACA to obtained some experimental verification of the formulas are described next. Finally, the formulas are applied to a s… more
Date: June 1935
Creator: Kuhn, Paul
Item Type: Refine your search to only Report
open access

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.
Item Type: Refine your search to only Report
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