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Wind-Tunnel Tests and Analysis of Three 10-Foot-Diameter Three-Blade Tractor Propellers Differing in Pitch Distribution

Description: Report discussing an investigation of the effect of variations in pitch distribution on propeller efficiency at low Mach numbers. The three 10-foot-diameter propellers tested consisted of three blades mounted on a streamline body and were tested for a blade-angle range from 15 degrees to 60 degrees. Information about the propeller thrust, power coefficients, force-balance measurements, and total pressure in the propeller wake is provided.
Date: August 1946
Creator: Gilman, Jean, Jr.
Partner: UNT Libraries Government Documents Department
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Charts for the Minimum-Weight Design of 24S-T Aluminum-Alloy Flat Compression Panels With Longitudinal Z-Section Stiffeners

Description: Report presenting design charts for 24S-T aluminum-alloy flat compression panels with longitudinal Z-section stiffeners. It was found that maximum possible structural efficiency with these panels requires closer stiffener spacings than those now in common use.
Date: August 1945
Creator: Schuette, Evan H.
Partner: UNT Libraries Government Documents Department
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Comparisons of Methods of Computing Bending Moments in Helicopter Rotor Blades in the Plane of Flapping

Description: Report presenting several methods of computing bending moments in helicopter rotor blades in the plane of flapping, and the results of a numerical example analyzed by four different methods are compared. The effect of computed bending moments of the tip-loss correction introduced by Wheatley is also considered.
Date: August 1945
Creator: Duberg, John E. & Luecker, Arthur R.
Partner: UNT Libraries Government Documents Department
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Elimination of Galling of Pendulum-Vibration Dampers Used in Aircraft Engines

Description: Report presenting an analysis of the contact stresses in a damper installation of an aircraft engine that indicated that galling could be eliminated by increasing the diameters of damper pins and holes. Torsional-vibration pendulum dampers have been successful in minimizing vibrations at critical speeds in aircraft engines, but serious wearing problems are often encountered when using them. The damper used in this experiment did not suffer any type of damage after many hours of use.
Date: August 1945
Creator: Meyer, André J., Jr.
Partner: UNT Libraries Government Documents Department
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Heat-Transfer Tests of Aqueous Ethylene Glycol Solutions in an Electrically Heated Tube

Description: "As part of an investigation of the cooling characteristics of liquid-cooled engines, tests were conducted with an electrically heated single-tube heat exchanger to determine the heat-transfer characteristics of AN-E-2 ethylene glycol and other ethylene glycol-water mixtures. Similar tests were conducted with water and commercial butanol (n-butyl alcohol) for check purposes. The results of tests conducted at an approximately constant liquid-flow rate of 0.67 pound per second (Reynolds number, 1… more
Date: August 1945
Creator: Bernardo, Everett & Eian, Carroll S.
Partner: UNT Libraries Government Documents Department
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Hinge Moments of Sealed-Internal-Balance Arrangements for Control Surfaces 1: Theoretical Investigation

Description: Report presenting the results of a theoretical analysis of the hinge-moment characteristics of various sealed-internal-balance arrangements for control surfaces. The results of the investigation indicated that the most nearly linear control-surface hinge-moment characteristics can probably be obtained from a flexible seal over a narrow gap, which is so installed that the motion of the seal is restricted to a region behind the point of attachment of the seal to the wing structure.
Date: August 1945
Creator: Murray, Harry E. & Erwin, Mary A.
Partner: UNT Libraries Government Documents Department
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Hinge Moments of Sealed-Internal-Balance Arrangements for Control Surfaces 2: Experimental Investigation of Fabric Seals in the Presence of a Thin-Plate Overhang

Description: Report presenting tests in a seal test chamber to determine the hinge moments contributed by the fabric seal in an internal-balance arrangement employing a thin-plate overhang. The tests were performed with various widths of fabric sealing various widths of flap-nose gap, with a horizontal, a vertical, and a circular type of wing structure forward of the balance, and with various heights of balance chamber. Results regarding seal-profile photographs, desired seal-moment characteristics, experim… more
Date: August 1945
Creator: Fischel, Jack
Partner: UNT Libraries Government Documents Department
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Infrared-spectrophotometric analysis of binary and ternary mixtures of liquid hydrocarbons

Description: Report presenting an investigation to determine the suitability and precision of a modified, routine-model, infrared spectrophotometer for analyzing binary and ternary mixtures of aircraft-fuel components. Analyses by means of infrared measurements are described for the following hydrocarbon mixtures: 12 known mixtures of 2,2,3-trimethylbutane (triptane) and cyclohexane, 4 known mixtures of triptane and benzene, and 4 known mixtures of triptane, cyclohexane, and benzene.
Date: August 1945
Creator: Cleaves, Alden P. & Sherrick, Mildred E.
Partner: UNT Libraries Government Documents Department
open access

An Investigation of Aircraft Heaters 18: A Design Manual for Exhaust Gas and Air Heat Exchangers

Description: Report presenting a summary of a series of reports regarding heat exchangers, and in particular, the design of exhaust gas and air heat exchangers. The four parts included are a summary of heat transfer equations, single pass heat exchangers, heater performance in flight, and appendicies with additional aerodynamic information.
Date: August 1945
Creator: Boelter, L. M. K.; Martinelli, R. C.; Romie, F. E. & Morrin, E. H.
Partner: UNT Libraries Government Documents Department
open access

Investigation of Effect of Sideslip on Lateral Stability Characteristics 3: Rectangular Low Wing on Circular Fuselage With Variations in Vertical-Tail Area and Fuselage Length With and Without Horizontal Tail Surface

Description: Report presenting power-off tests made in the 6- by 6-foot test section of the stability tunnel to determine the variation of the static lateral stability characteristics with vertical-tail area, fuselage length, and wing dihedral. The results are presented as curves showing the variation of the static-lateral-stability slopes with angle of attack, and the rolling-moment, yawing-moment, and lateral-force coefficients with angle of yaw.
Date: August 1945
Creator: Hollingworth, Thomas A.
Partner: UNT Libraries Government Documents Department
open access

Lifting-Surface-Theory Values of the Damping in Roll and of the Parameter Used in Estimating Aileron Stick Forces

Description: Report presenting an investigation by lifting-surface theory of a thin elliptic wing of aspect ratio 6 in a steady roll by means of the electromagnetic-analogy method. The results obtained by lifting-surface theory indicate that the damping in roll for a wing of aspect ratio of 6 is 13 percent less than that give by lifting-line theory and 5 percent less than that given by lifting-line theory with the edge-velocity correction derived by Robert T. Jones applied. Simple practical methods of apply… more
Date: August 1945
Creator: Swanson, Robert S. & Priddy, E. LaVerne
Partner: UNT Libraries Government Documents Department
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Piston-Ring Vibration and Breakage

Description: Report presenting testing to determine the stresses and bending moments required to break pieces 1 inch or less in length from the ends of cast-iron, keystone, compression piston rings. Strain gages were used to determine the stress pattern for various modes of vibration. The maximum-stress points of vibrating piston rings were at the antinodes or points of maximum deflection.
Date: August 1945
Creator: Nettles, J. C. & Meyer, André J., Jr.
Partner: UNT Libraries Government Documents Department
open access

Stability and Control Characteristics of a Fighter Airplane in Inverted Flight Attitude as Determined by Model Tests

Description: Report discuss the results of force tests, yaw-trim tests, and power-off tests to compare the stability and control characteristics of a powered airplane model in the erect and inverted flight attitudes. Due to the violent and uncontrollable maneuvers that sometimes occur after flight in the inverted attitude, more information was requested about stability and control characteristics in this position. Testing found that with the power on, a serious reduction in longitudinal and directional stab… more
Date: August 1945
Creator: Paulson, John W. & Bennett, Charles V.
Partner: UNT Libraries Government Documents Department
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Standard Method of Graphical Presentation of Centrifugal Compressor Performance

Description: Report on the NACA recommended method for comparing the performance of centrifugal compressors. The most important indices of compressor performance are the adiabatic temperature rise ratio or adiabatic efficiency, the adiabatic shaft efficiency, and the pressure ratio, which incorporate many other parameters. Recommendations for reporting on compressor effectiveness and characteristics are provided.
Date: August 1945
Creator: NACA Subcommittee on Supercharger Compressors
Partner: UNT Libraries Government Documents Department
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Standard Procedures for Rating and Testing Centrifugal Compressors

Description: Report on the NACA test-rig installation, measurements, instrumentation, test procedure, methods of calculation, and presentation of data for rating and testing centrifugal superchargers. Special precautions for certain portions of testing are also provided.
Date: August 1945
Creator: NACA Subcommittee on Supercharger Compressors
Partner: UNT Libraries Government Documents Department
open access

Stresses Near the Juncture of a Closed and an Open Torsion Box as Influenced by Bulkhead Flexibility

Description: Report discussing an open box joined to a closed box subjected to torsional loading. A stiff bulkhead and a flexible bulkhead were tested at the discontinuity and the results were compared to a previously published theory. Stress distribution was found to not be sensitive to bulkhead stiffness when the stiffness is large, but the calculations became sensitive to errors in estimating when the stiffness was small.
Date: August 1945
Creator: Kuhn, Paul & Brilmyer, Harold G.
Partner: UNT Libraries Government Documents Department
open access

Tests of a Linked Differential Flap System Designed to Minimize the Reduction in Effective Dihedral Caused by Power

Description: Report discusses the results of testing on a linked differential flap system upon the effective-dihedral characteristics of an airplane scale model. The negative dihedral changes caused by power can be materially reduced or eliminated by use of a differential flap system. The static directional stability also increased with differential flap action.
Date: August 1945
Creator: Pitkin, Marvin & Schade, Robert O.
Partner: UNT Libraries Government Documents Department
open access

Wind-tunnel tests of spoilers on tail surfaces

Description: Report presenting wind-tunnel testing in two-dimensional and three-dimensional flow to investigate the aerodynamic characteristics of spoilers on tail surfaces for low-speed flight. Test results indicated that spoilers on tail surfaces showed little possibility of replacing conventional control surfaces. Results regarding a flap alone, rear spoiler alone, forward spoiler alone, forward spoiler and flap, and a combination of forward and rear spoilers on upper and lower surfaces in both types of … more
Date: August 1945
Creator: Liddell, Robert B.
Partner: UNT Libraries Government Documents Department
open access

Continuous Use of Internal Cooling to Suppress Knock in Aircraft Engines Cruising at High Power

Description: Report presenting an investigation of the possibility of using internal cooling instead of fuel enrichment to suppress knock and to estimate the fuel savings that will result. Data from four different sources was examined and an analysis of the fuel consumption was conducted. Four different types of coolants were explored.
Date: August 1944
Creator: Bell, Arthur H.
Partner: UNT Libraries Government Documents Department
open access

An Experimental Investigation of the Thrust and Torque Produced by Propellers Used as Aerodynamic Brakes

Description: Report presenting the results of a wind-tunnel investigation of propellers operating at negative thrust. Negative-thrust characteristics of two- and four-blade single propellers and four- and eight-blade dual propellers were determined. The results indicate that the constant-speed reversed-pitch propellers posses aerodynamic characteristics that should make them excellent aerodynamic brakes.
Date: August 1944
Creator: Hedrick, William S. & Douglass, William M.
Partner: UNT Libraries Government Documents Department
open access

An Investigation of Aircraft Heaters 14: Performance of Two Finned-Type Crossflow Exhaust Gas and Air Heat Exchangers

Description: Report presenting data on the thermal performance and the static pressure drop characteristics of two finned-type exhaust gas and air heat exchangers. One heater was constructed of copper and stainless steel while the other was constructed from aluminum alloy. The measured thermal outputs and static pressure drops are compared with predicted magnitudes.
Date: August 1944
Creator: Boelter, L. M. K.; Guibert, A. G.; Rademacher, J. M. & Sloggy, L. J. B.
Partner: UNT Libraries Government Documents Department
open access

An investigation of aircraft heaters 17: experimental inquiry into steady state unidirectional heat-meter corrections

Description: Report divided into two sections. One discusses a correction that must be applied to a heat meter when it is used at temperatures other than temperatures at which it was calibrated. The other section contains the results of an application of the two methods of correcting the heat-transfer rates for contact and heat-meter resistance to experimental data.
Date: August 1944
Creator: Boelter, L. M. K.; Poppendiek, H. F. & Gier, J. T.
Partner: UNT Libraries Government Documents Department
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