Search Results

open access

Spontaneous Combustion of Hydrogen

Description: It is shown by the author's experiments that hydrogen which escapes to the atmosphere through openings in the system may burn spontaneously if it contains dust. Purely thermal reasoning can not account for the combustion. It seems to be rather an electrical ignition. In order to determine whether the cause of the spontaneous ignition was thermo-chemical, thermo-mechanical, or thermo-electrical, the experiments in this paper were performed.
Date: March 4, 1922
Creator: Pothmann, P. & Nusselt, Wilhelm
Partner: UNT Libraries Government Documents Department
open access

Effects of a J34 Turbojet Engine on Supersonic Diffuser Performance

Description: Report presenting testing of a translating cone inlet with a variable bypass at Mach numbers 1.6, 1.8, and 2.0 with both a choked exit plug and a J34 turbojet engine. The main difference between the two options was increased inlet subcritical stability with the engine. Results regarding basic diffuser performance, inlet stability, buzz amplitude and frequency, and diffuser-exit profiles are provided.
Date: January 4, 1956
Creator: Beheim, Milton A. & Englert, Gerald W.
Partner: UNT Libraries Government Documents Department
open access

Effect of an Adjustable Supersonic Inlet on the Performance Up to Mach Number 2.0 of a J34 Turbojet Engine

Description: "A J34 turbojet engine was investigated at free-stream Mach numbers of 0.12 and 1.6 to 2.0 to determine the effect of supersonic inlet operation on engine performance. With the exception of ideal jet thrust, the use of generalized engine parameters correlated the engine data satisfactorily when the exit nozzle was choked. Large total-pressure distortions did not affect compressor efficiency" (p. 1).
Date: January 4, 1956
Creator: Beke, Andrew; Englert, Gerald & Beheim, Milton
Partner: UNT Libraries Government Documents Department
open access

Calculated Heats of Formation and Combustion of Boron Compounds (Boron, Hydrogen, Carbon, Silicon)

Description: Memorandum presenting the calculation of the heats of formation and combustion for liquid and gaseous alkyl- and silyl-substituted boron compounds by a semitheoretical method. The results indicated that alkylation and more especially silylation reduce the heat of combustion. Results regarding alkyl- and silyldecaboranes, diborylmethane, diborylethane, and their alkyl derivatives, bipentaboranyl and bideocaboranyl, dipentaboranyl- and didecaboranylalkanes, and heats of combustion of isomers are … more
Date: October 4, 1955
Creator: Altshuller, Aubrey P.
Partner: UNT Libraries Government Documents Department
open access

Application of Pulse Techniques to Strain Gages

Description: Memorandum presenting pulse techniques applied to strain gages for increasing the output level and extending the usable range. Bonded and unbonded strain gages which normally operate with exciting potentials between 3.5 and 14 volts operated satisfactorily with 200-volt pulses of 1-microsecond duration and a repetition rate of 350 per second. Results regarding maximum allowable voltages, effective pulse duration, sensitivity, minimum readable signal, effects of cable capacitance and inductance,… more
Date: May 4, 1954
Creator: Sanders, Newell D. & Brodie, George H.
Partner: UNT Libraries Government Documents Department
open access

Nonlifting Wing-Body Combinations With Certain Geometric Restraints Having Minimum Wave Drag at Low Supersonic Speeds

Description: "Several variational problems involving optimum wing and body combinations having minimum wave drag for different kinds of geometrical restraints are analyzed. Particular attention is paid to the effect on the wave drag of shortening the fuselage and, for slender axially symmetric bodies, the effect of fixing the fuselage diameter at several points or even of fixing whole portions of its shape" (p. 113).
Date: August 4, 1955
Creator: Lomax, Harvard
Partner: UNT Libraries Government Documents Department
open access

Theoretical analysis of incompressible flow through a radial-inlet centrifugal impeller at various weight flows

Description: A method for the solution of the incompressible nonviscous flow through a centrifugal impeller, including the inlet region, is presented. Several numerical solutions are obtained for four weight flows through an impeller at one operating speed. These solutions are refined in the leading-edge region. The results are presented in a series of figures showing streamlines and relative velocity contours. A comparison is made with the results obtained by using a rapid approximate method of analysis.
Date: March 4, 1955
Creator: Kramer, James J.; Prian, Vasily D. & Wu, Chung-Hua
Partner: UNT Libraries Government Documents Department
open access

Studies of the speed stability of a tandem helicopter in forward flight

Description: Flight-test measurements, related analytical studies, and corresponding pilots' opinions of the speed stability of tandem-rotor helicopter are presented. An undesirable instability, evidenced by rearward stick motion with increasing forward speed at constant power, is indicated to be caused by variations with speed of the front-rotor downwash at the rear rotor. An analytical expression for predicting changes in speed stability caused by changes in rotor geometry is derived and constants for use… more
Date: June 4, 1953
Creator: Tapscott, Robert J. & Amer, Kenneth B.
Partner: UNT Libraries Government Documents Department
open access

Static Lateral-Directional Stability Characteristics of Five Contemporary Airplane Models From Wind-Tunnel Tests at High Subsonic and Supersonic Speeds

Description: Memorandum presenting the static lateral-directional stability characteristics of several airplane models recently investigated which cover many of the geometric arrangements of high-speed airplane components of current interest. The results are limited to the most pertinent aerodynamic phenomena contributing to the lateral-directional characteristics of each airplane type. Results for five different models are provided.
Date: January 4, 1956
Creator: Smith, Willard G. & Ball, Louis H.
Partner: UNT Libraries Government Documents Department
open access

Aerodynamic Characteristics at a Mach Number of 6.8 of Two Hypersonic Missile Configurations, One With Low-Aspect-Ratio Cruciform Fins and Trailing-Edge Flaps and One With a Flared Afterbody and All-Movable Controls

Description: Report presenting an investigation to determine the aerodynamic characteristics in pitch at a Mach number of 6.8 of hypersonic missile configurations with cruciform trailing-edge flaps and all-movable control surfaces. Testing indicated that all-movable controls on the flared-afterbody model should be capable of producing much larger values of trim lift and of normal acceleration than the trailing-edge-flap configuration. Some of the configurations tested include body alone, body with 5 degree … more
Date: August 4, 1958
Creator: Robinson, Ross B. & Bernot, Peter T.
Partner: UNT Libraries Government Documents Department
open access

Wind Tunnel Investigation at Low Speed of the Aerodynamic Characteristics of the Army Chemical Corps Model E112 Bomblets

Description: Report discussing an experimental investigation to determine the aerodynamic characteristics of the Army Chemical Corps model E112 bomblets. From Summary: "A detailed analysis has not been made; however, the results showed that a gap between model tips and the end plates or increasing the end-plate size for a solid model could result in a spirally stable configuration." A large amount of data collected from testing and photographs of the model are provided.
Date: November 4, 1955
Creator: Letko, William & Williams, James L.
Partner: UNT Libraries Government Documents Department
open access

Longitudinal Aerodynamic Characteristics of Various Configurations of a Revised 1/22-Scale Model of the Republic F-105 Airplane at Mach Numbers of 1.41 and 2.01

Description: Report presenting an investigation of a model of the Republic F-105 airplane to determine the static longitudinal aerodynamic characteristics of a revised configuration. The revisions included a lengthened fuselage, a relocated canopy, a contoured fuselage afterbody, a ventral fin, and an enlarged vertical tail. Results regarding the effect of stores, effect of dive-brake flaps, effect of forebody modifications, gun blisters, and duct air bleed, and a comparison of the modified model with the o… more
Date: May 4, 1956
Creator: Foster, Gerald V.
Partner: UNT Libraries Government Documents Department
open access

Preliminary Investigation of Cyclic De-Icing of an Airfoil Using an External Electric Heater

Description: "An investigation was conducted in the NACA Lewis icing research tunnel to determine the characteristics and requirements of cyclic deicing of a 65,2-216 airfoil by use of an external electric heater. The present investigation was limited to an airspeed of 175 miles per hour. Data are presented to show the effects of variations in heat-on and heat-off periods, ambient air temperature, liquid-water content, angle of attack, and. heating distribution on the requirements for cyclic deicing" (p. 1). more
Date: February 4, 1952
Creator: Lewis, James P. & Bowden, Dean T.
Partner: UNT Libraries Government Documents Department
open access

General Potential Theory of Arbitrary Wing Sections

Description: The problem of determining the two dimensional potential flow around wing sections of any shape is examined. The problem is condensed into the compact form of an integral equation capable of yielding numerical solutions by a direct process. An attempt is made to analyze and coordinate the results of earlier studies relating to properties of wing sections. The existing approximate theory of thin wing sections and the Joukowski theory with its numerous generalizations are reduced to special cases… more
Date: November 4, 1932
Creator: Theodorsen, T. & Garrick, I. E.
Partner: UNT Libraries Government Documents Department
open access

Wind-Tunnel Investigation of a 0.6-Scale Model of Hughes MX-904 Tail Surface at Supersonic Speeds: Tail Attached to a Segment of the Foreshortened Body

Description: "An investigation has been made of a partial-span model of the tail surface designed for use on the Hughes Falcon (MX-904) missile to determine the aerodynamic characteristics of the tail and elevator including elevator hinge moment. Data obtained at Mach numbers of 1.62 and 1.96 in the Langley 9- by 12-inch supersonic blowdown tunnel are presented for the condition where the tail was attached to a segment of the foreshortened body" (p. 1).
Date: May 4, 1950
Creator: Conner, D. William & Guy, Lawrence D.
Partner: UNT Libraries Government Documents Department
open access

Preliminary Flight Measurements of the Total-Pressure Recovery of a Split-Wing Ram-Jet Inlet at Mach Numbers from 1.4 to 3.16

Description: "Flight tests were made to determine the total-pressure recovery of a split-wing ram-jet inlet with a fixed area exit 20 percent larger than the inlet throat over a Mach number range from 1.4 to 3.16. Total-pressure-recovery measurements at the diffuser exist station indicated abrupt pressure changes in the total-pressure profile throughout the Mach number range. Comparisons of average total-pressure recovery with the theoretical total-pressure recovery showed good agreement" (p. 1).
Date: March 4, 1954
Creator: Hinners, Arthur H., Jr.
Partner: UNT Libraries Government Documents Department
open access

Comparison of Injectors With a 200-Pound-Thrust Ammonia-Oxygen Engine

Description: "Characteristic exhaust velocity was measured for a small range of mixture ratios with four different injectors. Performances of parallel-sheet, like-on-like, and triplet injectors were about the same, but a parallel-jet injector had a much lower performance. Performance values for ammonia-oxygen were slightly lower than for heptane-oxygen" (p. 1).
Date: September 4, 1958
Creator: Priem, Richard J. & Clark, Bruce J.
Partner: UNT Libraries Government Documents Department
open access

The Effect of Several Jet-Engine Air-Inlet Configurations on the Low-Speed Static Lateral Stability Characteristics of a 1/6- Scale of the MX-1764 Airplane

Description: Memorandum presenting an investigation in the 7- by 10-foot tunnel to determine the effect of wing-root leading-edge- and scoop-type jet-engine air-inlet configurations on the static lateral stability characteristics of a scale model of the MX-1764 airplane. The addition of the inlet configurations to the model generally had only small effects on the lateral stability.
Date: March 4, 1954
Creator: Croom, Delwin R.
Partner: UNT Libraries Government Documents Department
open access

Experimental and Analytical Investigation of the Transonic and Supersonic Divergence Characteristics of a Delta-Plan-Form All-Movable Control

Description: "The static aeroelastic divergence characteristics of a delta-plan-form model of the canard control surface of a proposed air-to-ground missile have been studied both analytically and experimentally in the Mach number range from 0.6 to 3.0. The experiments indicated that divergence occurred at a nearly constant value of dynamic pressure at Mach numbers up to 1.2. At higher Mach numbers somewhat higher values of dynamic pressure were required to produce divergence" (p. 1).
Date: August 4, 1958
Creator: Rainey, A. Gerald; Hanson, Perry W. & Martin, Dennis J.
Partner: UNT Libraries Government Documents Department
open access

Use of Constant Diffuser Mach Number as a Control Parameter for Variable-Geometry Inlets at Mach Numbers of 1.8 to 2.0

Description: Memorandum presenting an analysis to determine the feasibility of using a constant diffuser Mach number to position a translating spike for optimum inlet performance. A control system incorporating this concept was investigated on a blunt lip, translating-spike inlet at flight Mach numbers of 1.8 to 2.0 and angles of attack up to 6 degrees. Results regarding inlet characteristics and performance with control are provided.
Date: November 4, 1957
Creator: Hearth, Donald P. & Anderson, Bernhard H.
Partner: UNT Libraries Government Documents Department
open access

Longitudinal Stability and Control of High-Speed Airplanes With Particular Reference to Dive Recovery

Description: "An analysis of the effects of compressibility on the longitudinal stability, control, and trim of airplanes flying at high subsonic speeds and a discussion of the causes of and the means for lessening or preventing the diving tendency are presented. Wind-tunnel results for Mach numbers up to 0.90 are included for purposes of illustration and cover several investigations of longitudinal stability and control, airfoil characteristics, dive-recovery aids, and elevator characteristics. Methods are… more
Date: September 4, 1947
Creator: Axelson, John A.
Partner: UNT Libraries Government Documents Department
open access

Effects of Combinations of Aspect Ratio and Sweepback at High Subsonic Mach Numbers

Description: Report discussing an investigation to determine the effects of sweepback and low aspect ratio on the aerodynamic characteristics of a wing at high subsonic Mach numbers. Tests were performed at aspect ratios of 2, 3, and 5 and sweepback angles of 0, 30, and 45 degrees. Generally, sweepback and low aspect ratio were found to both delay and lessen the effects of compressibility.
Date: June 4, 1947
Creator: Adler, Alfred A.
Partner: UNT Libraries Government Documents Department
open access

Aerodynamic Characteristics of a 45 Degree Swept-Back Wing With Aspect Ratio of 3.5 and NACA 2S-50(05)-50(05) Airfoil Sections

Description: From Introduction: "The present paper presents the scale effect on the longitudinal aerodynamic characteristics, the aerodynamic characteristics in yaw, and the tuft studies for 0^o and 3.7^o yaw. The results of the effect of leading-edge and trailing-edge flaps on the aerodynamic characteristics of the wing will be presented in later reports."
Date: August 4, 1947
Creator: Proterra, Anthony J.
Partner: UNT Libraries Government Documents Department
open access

High-speed wind-tunnel investigation of the effects of compressibility on a pitot-static tube

Description: Report presenting a high-speed wind-tunnel investigation of a pitot-static tube to provide information on the effects of compressibility upon the pressure indications of a representative airspeed head at high subsonic speeds. The calibration factor for the instrument has been evaluated for several small angles of pitch and yaw throughout a Mach number range from 0.30 to approximately 0.925. The results indicate that the calibration factor for each combination of pitch and yaw angles tested is a… more
Date: August 4, 1947
Creator: Stivers, Louis S., Jr. & Adams, Charles N., Jr.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen