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Considerations of the Take-Off Problem

Description: Many technical papers on the various phases of airplane take-off have been published. Frequently, however, there appear new ideas which affect only particular scattered phases of the subject and which do not receive individual publication. It is the purpose of this paper to present several ideas of this nature which may be of considerable aid in calculating take-off performance and one idea which should correct what appears to be a popular misconception of the importance of static propeller thr… more
Date: February 1936
Creator: Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Tests of a 2-Engine Airplane Model as a Preliminary Study of Flight Conditions Arising on the Failure of the Engine

Description: "Wind tunnel tests of a 15-foot-span model of a two-engine low wing transport airplane were made as a preliminary study of the emergency arising from the failure of one engine in flight. Two methods of reducing the initial yawing moment resulting from the failure of one engine were investigated and the equilibrium conditions were explored for two basic modes on one engine, one with zero angle of sideslip and the other with several degrees of sideslip. The added drag resulting from the unsymmetr… more
Date: April 1938
Creator: Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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A Method of Calculating the Performance of Controllable Propellers With Sample Computations

Description: "This paper contains a series of calculations showing how the performance of controllable propellers may be derived from data on fixed-pitch propellers given in N.A.C.A. Technical Report No. 350, or from similar data. Sample calculations are given which compare the performance of airplanes with fixed-pitch and with controllable propellers. The gain in performance with controllable propellers is shown to be largely due to the increased power available, rather than to an increase in efficiency" (… more
Date: January 1934
Creator: Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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Negative Thrust and Torque Characteristics of an Adjustable-Pitch Metal Propeller

Description: This report presents the results of a series of negative thrust and torque measurements made with a 4 foot diameter model of a conventional aluminum-alloy propeller. The tests were made in the 20-foot propeller-research tunnel of the National Advisory Committee for Aeronautics. The results show that the negative thrust is considerably affected by the shape and size of the body behind the propeller, that the maximum negative thrust increases with decrease in blade-angle setting, and that the dra… more
Date: May 23, 1933
Creator: Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
open access

Wind-Tunnel Tests of Four- and Six-Blade Single- and Dual-Rotating Tractor Propellers

Description: "Test of 10-foot diameter, four and six blade single-rotating and dual-rotating propellers were conducted in the NACA propeller-research tunnel. The propellers were mounted at the front end of a streamline body incorporating spinners to house the hub portions. The effect of a symmetrical wing mounted in the slipstream ranged from 20 degrees to 65 degrees setting corresponds to airplane speeds greater than 500 miles per hour. The results indicate that dual-rotating propellers were from 0 to 6 pe… more
Date: July 13, 1942
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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Static Thrust and Power Characteristics of Six Full-Scale Propellers

Description: "Static thrust and power measurements were made of six full-scale propellers. The propellers were mounted in front of a liquid-cooled-engine nacelle and were tested at 15 different blade angles in the range from -7 1/2 degrees to 35 degrees at 0.75r. The test rig was located outdoors and the tests were made under conditions of approximately zero wind velocity" (p. 85).
Date: January 25, 1939
Creator: Hartman, Edwin P. & Biermann, David
Partner: UNT Libraries Government Documents Department
open access

Tests of Two Full-Scale Propellers With Different Pitch Distributions, at Blade Angles Up to 60 Degrees

Description: "Two 3-blade 10-foot propellers were operated in front of a liquid-cooled engine nacelle. The propellers differed only in pitch distribution; one had normal distribution (nearly constant pitch for a blade angle of 15 degrees at 0.75 radius), and the other had the pitch of the tip sections decreased with respect to that for the shank sections (blade angle of 35 degrees for nearly constant pitch distribution). Propeller blade angles at 0.75r from 15 degrees to sixty degrees, corresponding to desi… more
Date: April 14, 1938
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
open access

Full-Scale Tests of 4- and 6-Blade, Single- and Dual-Rotating Propellers, Special Report

Description: "Test of 10-foot diameter, 4- and 6-blade single- and dual-rotating propellers were conducted in the 20-foot propeller-research tunnel. The propellers were mounted at the front end of a streamline body incorporating spinners to house the hub portions. The effect of a symmetrical wing mounted in the slipstream was investigated. The blade angles investigated ranged from 20 degrees to 65 degrees; the latter setting corresponds to airplane speeds of over 500 miles per hour" (p. 1).
Date: August 1940
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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The Torsional and Bending Deflection of Full-Scale Duralumin Propeller Blades Under Normal Operating Conditions, Special Report

Description: "The torsional deflection of the blades of three full-scale duralumin propellers operating under various loading conditions was measured by a light-beam method. Angular bending deflections were also obtained as an incidental part of the study. The deflection measurements showed that the usual present-day type of propeller blades twisted but a negligible amount under ordinary flight conditions. A maximum deflection of about 1/10th of a degree was found at V/nD of 0.3 and a smaller deflection at … more
Date: March 1938
Creator: Hartman, Edwin P. & Biermann, David
Partner: UNT Libraries Government Documents Department
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Tests of Five Full-Scale Propellers in the Presence of a Radial and a Liquid-Cooled Engine Nacelle, Including Tests of Two Spinners

Description: "Wind-tunnel tests are reported of five 3-blade 10-foot propellers operating in front of a radial and a liquid-cooled engine nacelle. The range of blade angles investigated extended from 15 degrees to 45 degrees. Two spinners were tested in conjunction with the liquid-cooled engine nacelle. Comparisons are made between propellers having different blade-shank shapes, blades of different thickness, and different airfoil sections" (p. 589).
Date: 1938
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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The Effect of Compressibility on Eight Full-Scale Propellers Operating in the Take-Off and Climbing Range

Description: "Tests were made of eight full-scale propellers of different shape at various tip speeds up to about 1,000 feet per second. The range of blade-angle settings investigated was from 10 degrees to 30 degrees at the 0.75 radius. The results indicate that a loss in propulsive efficiency occurred at tip speeds from 0.5 to 0.7 the velocity of sound for the take-off and climbing conditions" (p. 517).
Date: May 18, 1938
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
open access

The Aerodynamic Characteristics of Full-Scale Propellers Having 2, 3, and 4 Blades of Clark Y and R.A.F. 6 Airfoil Sections

Description: "Aerodynamic tests were made of seven full-scale 10-foot-diameter propellers of recent design comprising three groups. The first group was composed of three propellers having Clark Y airfoil sections and the second group was composed of three propellers having R.A.F. 6 airfoil sections, the propellers of each group having 2, 3, and 4 blades. The third group was composed of two propellers, the 2-blade propeller taken from the second group and another propeller having the same airfoil section and… more
Date: 1938
Creator: Hartman, Edwin P. & Biermann, David
Partner: UNT Libraries Government Documents Department
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The Negative Thrust and Torque of Several Full-Scale Propellers and Their Application to Various Flight Problems

Description: "Negative thrust and torque data for 2, 3, and 4-blade metal propellers having Clark y and R.A.F. 6 airfoil sections were obtained from tests in the NACA 20-foot tunnel. The propellers were mounted in front of a radial engine nacelle and the blade-angle settings covered in the tests ranged from 15 degrees to 90 degrees. One propeller was also tested at blade-angle settings of 0 degree, 5 degrees, and 10 degrees" (p. 571).
Date: 1938
Creator: Hartman, Edwin P. & Biermann, David
Partner: UNT Libraries Government Documents Department
open access

The Torsional and Bending Deflection of Full-Scale Aluminum-Alloy Propeller Blades Under Normal Operating Conditions

Description: "The torsional deflection of the blades of three full-scale aluminum-alloy propellers operating under various loading conditions was measured by a light-beam method. Angular bending deflections were also obtained as an incidental part of the study. The deflection measurements showed that the usual present-day type of propeller blades twisted but a negligible amount under ordinary flight conditions. A maximum deflection of about 1/10 degree was found at a v/nd of 0.3 and a smaller deflection at … more
Date: 1938
Creator: Hartman, Edwin P. & Biermann, David
Partner: UNT Libraries Government Documents Department
open access

The aerodynamic characteristics of four full-scale propellers having different plan forms

Description: From Introduction: "Its main purpose is to present propeller data for four full-scale propellers of Navy design, three of which have somewhat unusual plan forms and the other one has a normal (usual present-day type) plan form. These data may give some clue as to what may be expected from fundamental changes in blade plan form."
Date: 1938~
Creator: Hartman, Edwin P. & Biermann, David
Partner: UNT Libraries Government Documents Department
open access

The aerodynamic characteristics of six full-scale propellers having different airfoil sections

Description: From Summary: "Wind-tunnel tests are reported of six 3-blade 10-foot propellers operated in front of a liquid-cooled engine nacelle. The propellers were identical except for blade airfoil sections, which were: Clark y, R.A.F. 6, NACA 4400, NACA 2400-34, NACA 2rsub200, and NACA 6400. The range of blade angles investigated extended for 15 degrees to 40 degrees for all propellers except the Clark y, for which it extended to 45 degrees. The results showed that the range in maximum efficiency betwee… more
Date: 1939
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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Hydrodynamic and Aerodynamic Tests of Four Models of Outboard Floats: (N.A.C.A. Models 51-A, 51-B, 51-C, and 51-D)

Description: Four models of outboard floats (N.A.C.A. models 51-A, 51-B, 51-C, and 51-D) were tested in the N.A.C.A. tank to determine their hydrodynamic characteristics and in the 20-foot wind tunnel to determine their aerodynamic drag. The results of the tests, together with comparisons of them, are presented in the form of charts. From the comparisons, the order of merit of the models is estimated for each factor considered. The best compromise between the various factors seems to be given by model 51-D.… more
Date: December 1938
Creator: Dawson, John R. & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
open access

Full-Scale Tests of Several Propellers Equipped with Spinners, Cuffs, Airfoil and Round Shanks, and NACA 16-Series Sections, Special Report

Description: "Wind-tunnel tests of several propeller, cuff, and spinner combinations were conducted in the 20 foot propeller-research tunnel. Three propellers, which ranged in diameter from 8.4 to 11.25 feet, were tested at the front end of a streamline body incorporating spinners of two diameters. The tests covered a blade angle range from 20 deg to 65 deg. The effect of spinner diameter and propeller cuffs on the characteristics of one propeller was determined" (p. 1).
Date: October 1940
Creator: Biermann, David; Hartman, Edwin P. & Pepper, Edward
Partner: UNT Libraries Government Documents Department
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