Spin Tests of a Low-Wing Monoplane to Investigate Scale Effect in the Model Test Range (open access)

Spin Tests of a Low-Wing Monoplane to Investigate Scale Effect in the Model Test Range

"Concurrent tests were performed on a 1/16 and a 1/20 scale model (wing spans of 2.64 and 2.11 ft. respectively) of a modern low wing monoplane in the NACA 15 foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. Qualitatively, the same characteristic effects of control disposition, mass distribution, and dimensional modifications were indicated by both models" (p. 1).
Date: May 1941
Creator: Donlan, Charles J.
System: The UNT Digital Library
Propeller Design: Practical Application of the Blade Element Theory 1 (open access)

Propeller Design: Practical Application of the Blade Element Theory 1

"This report is the first of a series of four on propeller design and contains a description of the blade elements or modified Drzewiecke theory as used in the Bureau of Aeronautics, U.S. Navy Department. Blade interference corrections are used which were taken from R.& M. NO. 639 of the British Advisory Committee for Aeronautics. The airfoil characteristics used were obtained from tests of model propellers, not from tests of model wings" (p. 1).
Date: May 1926
Creator: Weick, Fred E.
System: The UNT Digital Library
The Estimation of Airplane Performance From Wind Tunnel Tests on Conventional Airplane Models (open access)

The Estimation of Airplane Performance From Wind Tunnel Tests on Conventional Airplane Models

Calculations of the magnitude of the correction factors and the range of their variations for wind tunnel models used in making aircraft performance predictions were made for 23 wind tunnel models. Calculated performances were compared with those actually determined for such airplanes as have been built and put through flight test. Except as otherwise noted, all the models have interplane struts and diagonal struts formed to streamwise shape. Wires were omitted in all cases. All the models were about 18 inches in span and were tested in a 4-foot wind tunnel. Results are given in tabular form.
Date: May 1925
Creator: Warner, Edward P. & Ober, Shatswell
System: The UNT Digital Library
Propeller Design: Extension of Test Data on a Family of Model Propellers by Means of the Modified Blade Element Theory 2 (open access)

Propeller Design: Extension of Test Data on a Family of Model Propellers by Means of the Modified Blade Element Theory 2

This report is the second of a series of four on propeller design, and describes the method used to extend the data obtained from tests on a family of thirteen model propellers to include all propellers of the same form likely to be met in practice. This necessitates the development of a method of propeller analysis which when used to calculate the powers and efficiencies gives results which check the tests throughout their range.
Date: May 1926
Creator: Weick, Fred E.
System: The UNT Digital Library
The comparison of well-known and new wing sections tested in the variable density wind tunnel (open access)

The comparison of well-known and new wing sections tested in the variable density wind tunnel

Three groups of airfoils have been tested in the variable density wind tunnel. The first group contains three airfoils. The second group is a systematic series of twenty-seven airfoils. The third group consists of several frequently used wing sections.
Date: May 1925
Creator: Higgins, George J.
System: The UNT Digital Library
Influence of Ribs on Strength of Spars (open access)

Influence of Ribs on Strength of Spars

Note presenting an investigation to determine what effect joints connected with brackets, nails, and glue has on the strength of aircraft wing spars. Equations used to determine the results of loading tests are provided.
Date: May 1923
Creator: Ballenstedt, L.
System: The UNT Digital Library
Propeller Design - A Simple System Based on Model Propeller Test Data -III (open access)

Propeller Design - A Simple System Based on Model Propeller Test Data -III

"This report, the third of a series of four, describes a simple system for designing propellers of a standard form. In this report, the system is based on tests of a family of model propellers of standard Navy form, the data from which have been extended by means of calculations to cover the complete range likely to be found in practice. However, it can be worked out for any family having propellers of one general form" (p. 1).
Date: May 1926
Creator: Wieck, Fred E.
System: The UNT Digital Library
Experiments With a Built-In or Fuselage Radiator (open access)

Experiments With a Built-In or Fuselage Radiator

"The experiments discussed here were performed to determine whether radiators having similar cooling properties offer less resistance when incorporated into the fuselage, than when the hitherto customary arrangement is employed, with the radiator in the free air current more or less independent of the fuselage. The experiments indicated that the quantity of air flowing through the radiator is greatest when the fuselage and the radiator are separate. However, separate radiators cause more air resistance" (p. 1).
Date: May 1923
Creator: Wieselsberger, C.
System: The UNT Digital Library
Lightning Discharges to Aircraft and Associated Meteorological Conditions (open access)

Lightning Discharges to Aircraft and Associated Meteorological Conditions

A summary is given of information on atmospheric electrical discharges to aircraft and associated meteorological conditions. Information is given that is designed to give a fairly comprehensive view of the underlying principles of meteorology and atmospheric electricity. Of special interest to pilots are lists of procedures of flight conduct and aircraft maintenance recommended foe avoiding or minimizing the hazards of disruptive electrical discharges and other severe conditions near thunderstorms.
Date: May 1946
Creator: Harrison, L. P.
System: The UNT Digital Library
Tank Tests of a Model of the NC Flying-Boat Hull - N.A.C.A. Model 44 (open access)

Tank Tests of a Model of the NC Flying-Boat Hull - N.A.C.A. Model 44

"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 trimming moment than model 11-A. At high speeds the best trim angle and the trimming moments of the two models are approximately the same" (p. 1).
Date: May 1936
Creator: Bell, Joe W.
System: The UNT Digital Library
Tests of N.A.C.A. airfoils in the variable-density wind tunnel. Series 230 (open access)

Tests of N.A.C.A. airfoils in the variable-density wind tunnel. Series 230

The results of tests of six airfoils having the N.A.C.A. 230 mean line and varying in thickness from 0.06c to 0.21c are presented. These results agree with previous findings in showing that aerodynamically the best section is one of moderate thickness. The data are of value mainly in connection with the design of tapered wings having sections based on the N.A.C.A. 230 mean line.
Date: May 1936
Creator: Jacobs, Eastman N. & Pinkerton, Robert M.
System: The UNT Digital Library
Compression-ignition engine tests of several fuels (open access)

Compression-ignition engine tests of several fuels

"The tests reported in this paper were made to devise simple engine tests which would rate fuels as to their comparative value and their suitability for the operating conditions of the individual engine on which the tests are made. Three commercial fuels were used in two test engines having combustion chambers with and without effective air flow. Strictly comparative performance tests gave almost identical results for the three fuels. Analysis of indicator cards allowed a differentiation between fuels on a basis of rates of combustion" (p. 1).
Date: May 1932
Creator: Spanogle, J. A.
System: The UNT Digital Library
Wind-tunnel tests of the Fowler variable-area wing (open access)

Wind-tunnel tests of the Fowler variable-area wing

The lift, drag, and center of pressure characteristics of a model of the Fowler variable-area wing were measured in the NACA 7 by 10 foot wind tunnel. The Fowler wing consists of a combination of a main wing and an extension surface, also of airfoil section. The extension surface can be entirely retracted within the lower rear portion of the main wing or it can be moved to the rear and downward. The tests were made with the nose of the extension airfoil in various positions near the trailing edge of the main wing and with the surface at various angular deflections. The highest lift coefficient obtained was C(sub L) = 3.17 as compared with 1.27 for the main wing alone.
Date: May 1932
Creator: Weick, Fred E. & Platt, Robert C.
System: The UNT Digital Library
The Effect of Propellers and Nacelles on the Landing Speeds of Tractor Monoplanes (open access)

The Effect of Propellers and Nacelles on the Landing Speeds of Tractor Monoplanes

"This paper reports wind-tunnel tests giving the lift coefficients of large-scale wing-nacelle combinations both with and without the propeller. The tests were made to show the effect of nacelles, and idling and stopped propellers on the landing speeds of tractor monoplanes. Four types of nacelles with various cowlings were used in numerous positions with respect to both a Clark Y and a thick airfoil. The effect of both the idling and stopped propeller on lift, and consequently on landing speed, was negligible" (p. 1).
Date: May 1932
Creator: Windler, Ray
System: The UNT Digital Library
The Nature of Air Flow About the Tail of an Airplane in a Spin (open access)

The Nature of Air Flow About the Tail of an Airplane in a Spin

"Air flow about the fuselage and empennage during a high-angle-of-attack spin was made visible in flight by means of titanium-tetrachloride smoke and was photographed with a motion-picture camera. The angular relation of the direction of the smoke streamer to the airplane axes was computed and compared with the angular direction of the motion in space derived from instrument measurement of the spin of the airplane for a nearly identical mass distribution. The results showed that the fin and upper part of the rudder were almost completely surrounded by dead air, which would render them inoperative; that the flow around the lower portion of the rudder and the fuselage was nonturbulent; and that air flowing past the cockpit in a high-angle-of-attack spin could not subsequently flow around control surfaces" (p. 1).
Date: May 1932
Creator: Scudder, N. F. & Miller, M. P.
System: The UNT Digital Library
The Aerodynamic Characteristics of a Model Wing Having a Split Flap Deflected Downward and Moved to the Rear (open access)

The Aerodynamic Characteristics of a Model Wing Having a Split Flap Deflected Downward and Moved to the Rear

"Tests were made on a model wing with three different sized split trailing-edged flaps, in the NACA 7 by 10 foot wind tunnel. The flaps were formed of the lower rear portion of the wing and were rotated downward about axes at their front edges. The lift, drag, and center of pressure were measured with the axis in its original position and also with it moved back in even steps to the trailing edge of the main wing, giving in effect an increase in area. The split flaps when deflected about their original axis locations gave slightly higher maximum lift coefficients than conventional trailing-edge flaps, and the lift coefficients were increased still further by moving the axes toward the rear" (p. 1).
Date: May 1932
Creator: Weick, Fred E. & Harris, Thomas A.
System: The UNT Digital Library
Calculated Effect of Various Types of Flap on Take-Off Over Obstacles (open access)

Calculated Effect of Various Types of Flap on Take-Off Over Obstacles

"In order to determine whether or not flaps could be expected to have any beneficial effect on take-off performance, the distances required to take off and climb to an altitude of 50 feet were calculated for hypothetical airplanes, corresponding to relatively high-speed types and equipped with several types of flap. The types considered are the Fowler wing, the Hall wing, the split flap, the balanced split flap, the plain flap, and the external-airfoil flap. The results indicate that substantial reductions in take-off distance are possible through the use of flaps, provided that the proper flap angle corresponding to a given set of conditions is used" (p. 1).
Date: May 1936
Creator: Wetmore, J. W.
System: The UNT Digital Library
Boosted Performance of a Compression-Ignition Engine With a Displaced Piston (open access)

Boosted Performance of a Compression-Ignition Engine With a Displaced Piston

From Summary: "Performance tests were made using a rectangular displacer arranged so that the combustion air was forced through equal passages at either end of the displacer into the vertical-disk combustion chamber of a single-cylinder, four-stroke-cycle compression-ignition test engine. After making tests to determine optimum displacer height, shape, and fuel-spray arrangement, engine-performance tests were made at 1,500 and 2,000 r.p.m. for a range of boost pressures from 0 to 20 inches of mercury and for maximum cylinder pressures up to 1,150 pounds per square inch. The engine operation for boosted conditions was very smooth, there being no combustion shock even at the highest maximum cylinder pressures. Indicated mean effective pressures of 240 pounds per square inch for fuel consumptions of 0.39 pound per horsepower-hour have been readily reproduced during routine testing at 2,000 r.p.m. at a boost pressure of 20 inches of mercury."
Date: May 1936
Creator: Moore, Charles S. & Foster, Hampton H.
System: The UNT Digital Library
Wind tunnel research comparing lateral control devices, particularly at high angles of attack 11: various floating tip ailerons on both rectangular and tapered wings (open access)

Wind tunnel research comparing lateral control devices, particularly at high angles of attack 11: various floating tip ailerons on both rectangular and tapered wings

Discussed here are a series of systematic tests being conducted to compare different lateral control devices with particular reference to their effectiveness at high angles of attack. The present tests were made with six different forms of floating tip ailerons of symmetrical section. The tests showed the effect of the various ailerons on the general performance characteristics of the wing, and on the lateral controllability and stability characteristics. In addition, the hinge moments were measured for the most interesting cases.
Date: May 1933
Creator: Weick, Fred E. & Harris, Thomas A.
System: The UNT Digital Library
Full-Scale Wind-Tunnel Research on Tail Buffeting and Wing-Fuselage Interference of a Low-Wing Monoplane (open access)

Full-Scale Wind-Tunnel Research on Tail Buffeting and Wing-Fuselage Interference of a Low-Wing Monoplane

Some preliminary results of full scale wind tunnel testing to determine the best means of reducing the tail buffeting and wing-fuselage interference of a low-wing monoplane are given. Data indicating the effects of an engine cowling, fillets, auxiliary airfoils of short span, reflexes trailing edge, propeller slipstream, and various combinations of these features are included. The best all-round results were obtained by the use of fillets together with the National Advisory Committee for Aeronautics (NACA) cowling.
Date: May 1933
Creator: Hood, Manley J. & White, James A.
System: The UNT Digital Library
The Effect of Rivet Heads on the Characteristics of a 6 by 36 Foot Clark Y Metal Airfoil (open access)

The Effect of Rivet Heads on the Characteristics of a 6 by 36 Foot Clark Y Metal Airfoil

"An investigation was conducted in the N.A.C.A. full-scale wind tunnel to determine the effects of exposed rivet heads on the aerodynamic characteristics of a metal-covered 6 by 36 foot Clark Y airfoil. Lead punching simulating 1/8 inch rivet heads were attached in full-span rows at a pitch of 1 inch at various chord positions. Tests were made at velocities varying from 40 to 120 miles per hour to investigate the scale effect" (p. 1).
Date: May 1933
Creator: Dearborn, Clinton H.
System: The UNT Digital Library
Strength tests of thin-walled duralumin cylinders of elliptic section (open access)

Strength tests of thin-walled duralumin cylinders of elliptic section

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 applied in the plane of the major axis. The results of the tests on elliptic cylinders are correlated with the results of corresponding tests on circular cylinders and are presented in charts suitable for use in design.
Date: May 1935
Creator: Lundquist, Eugene E. & Burke, Walter F.
System: The UNT Digital Library
Wind-tunnel tests of a cyclogiro rotor (open access)

Wind-tunnel tests of a cyclogiro rotor

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 and forward-flight conditions at several rotor speeds and the determination of the relations between the forces generated by the rotor and the power required by it.
Date: May 1935
Creator: Wheatley, John B. & Windler, Ray
System: The UNT Digital Library
Analysis of a Strut With a Single Elastic Support in the Span, With Applications to the Design of Airplane Jury-Strut Systems (open access)

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

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
System: The UNT Digital Library