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Theoretical Investigation of the Performance of Proportional Navigation Guidance Systems-Effect of Method of Positioning the Radar Antenna on the Speed of Response (open access)

Theoretical Investigation of the Performance of Proportional Navigation Guidance Systems-Effect of Method of Positioning the Radar Antenna on the Speed of Response

Memorandum presenting a linear theoretical analysis of the performance of three proportional navigation guidance systems installed in a given supersonic, variable-incidence, boost-glide, antiaircraft missile at Mach numbers of 2.7 and 1.3. It is shown that, with the antenna stabilized in space, the effect of component lags on the response is small, so that the speed of response is small, so that the speed of response can be made to approach closely that of the airframe alone.
Date: August 13, 1952
Creator: Abramovitz, Marvin
System: The UNT Digital Library
Theoretical Investigation of the Performance of Proportional Navigation Guidance Systems: Effect of Method of Positioning the Radar Antenna on the Speed of Response (open access)

Theoretical Investigation of the Performance of Proportional Navigation Guidance Systems: Effect of Method of Positioning the Radar Antenna on the Speed of Response

Memorandum presenting a linear theoretical analysis made of the performance of three proportional navigation guidance systems installed in a given supersonic, variable-incidence, boost-glide, antiaircraft missile at Mach numbers of 2.7 and 1.3. Three guidance systems are compared on the basis of the maximum obtainable speed of response of the missile and guidance-system combination consistent with adequate stability. Results regarding the effect of method of positioning the radar antenna on the speed of response, effect of Mach number on response, and effect of networks are provided.
Date: August 13, 1952
Creator: Abramovitz, Marvin
System: The UNT Digital Library
Theoretical Investigation of the Performance of Proportional Navigation Guidance Systems: Effect of Missile Configuration on the Speed of Response (open access)

Theoretical Investigation of the Performance of Proportional Navigation Guidance Systems: Effect of Missile Configuration on the Speed of Response

Memorandum presenting a comparison of the maximum speed of response that can be attained by three missile configurations, a variable-incidence-wing, a canard, and a tail-control, in combination with a particular proportional navigation guidance system. The configuration that allows the most rapid overall guidance-system response depends on the control-system characteristics. Results regarding the rate-only feedback and rate and normal acceleration feedback are provided.
Date: January 19, 1953
Creator: Abramovitz, Marvin
System: The UNT Digital Library
The effect of stick-force gradient and stick gearing on the tracking accuracy of a fighter airplane (open access)

The effect of stick-force gradient and stick gearing on the tracking accuracy of a fighter airplane

Report presenting steady straight-and-level and steady turning tracking runs against an aerial target using an F-51H airplane equipped with a fixed optical sight and with various combinations of maneuvering stick-force and stick-deflection gradients. Results regarding aim wander, elevator movement, and stick-force variation for various test conditions are provided.
Date: December 17, 1954
Creator: Abramovitz, Marvin & Van Dyke, Rudolph D., Jr.
System: The UNT Digital Library
Theoretical Investigation of the Effects of the Artificial-Feel System on the Maneuvering Characteristics of the F-89 Airplane (open access)

Theoretical Investigation of the Effects of the Artificial-Feel System on the Maneuvering Characteristics of the F-89 Airplane

The possibility of overshooting the anticipated normal acceleration as a result of the artificial-feel characteristics of the F-89C airplane at a condition of minimum static stability was investigated analytically by means of an electronic simulator. Several methods of improving the stick-force characteristics were studied. It is shown that, due to the lag in build-up of the portion of the stick force introduced by the bobweight, it would be possible for excessive overshoots of normal acceleration to occur in abrupt maneuvers with reasonable assumed control movements. The addition of a transient stick force proportional to pitching acceleration (which leads the normal acceleration) to prevent this occurring would not be practical due to the introduction of an oscillatory mode to the stick-position response. A device to introduce a viscous damping force would Improve the stick-force characteristics so that normal acceleration overshoots would not be likely, and the variation of the maximum stick force in rapid pulse-type maneuvers with duration of the maneuver then would have a favorable trend.
Date: December 31, 1952
Creator: Abramovitz, Marvin; Schmidt, Stanley F. & Belsley, Steven E.
System: The UNT Digital Library
Investigation of the Use of a Stick Force Proportional to Pitching Acceleration for Normal-Acceleration Warning (open access)

Investigation of the Use of a Stick Force Proportional to Pitching Acceleration for Normal-Acceleration Warning

Report presenting an investigation of the feasibility of modifying the transient portion of the stick force in abrupt maneuvers in order to eliminate inadvertent normal-acceleration overshoots. The modification consists of additional stick force proportional to a quantity which leads the normal acceleration. The characteristics introduced by the inclusion of the force were considered to be very desirable by pilots.
Date: August 14, 1953
Creator: Abramovitz, Marvin; Schmidt, Stanley F. & Van Dyke, Rudolph D., Jr.
System: The UNT Digital Library
Investigation of internal film cooling of exhaust nozzle of a 1000-pound-thrust liquid-ammonia liquid-oxygen rocket (open access)

Investigation of internal film cooling of exhaust nozzle of a 1000-pound-thrust liquid-ammonia liquid-oxygen rocket

Report presenting an investigation of internal film cooling of the exhaust nozzle of a 1000-pound-thrust liquid ammonia liquid-oxygen rocket engine. With water as a coolant, approximately 16 percent of the total propellant and coolant flow was required to film-cool the entire nozzle and with anhydrous liquid ammonia, approximately 19 percent of the total flow was required. Results regarding the coolant results and performance results are provided.
Date: June 17, 1952
Creator: Abramson, Andrew E.
System: The UNT Digital Library
Natural Icing of an Axial-Flow Turbojet Engine in Flight for a Single Icing Condition (open access)

Natural Icing of an Axial-Flow Turbojet Engine in Flight for a Single Icing Condition

Memorandum presenting an investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. A description of the change over time in tail-pipe temperature, engine jet thrust, fuel flow, ice collection, and acceleration qualities are provided.
Date: August 12, 1948
Creator: Acker, Loren W.
System: The UNT Digital Library
Preliminary Results of Natural Icing of an Axial-Flow Turbojet Engine (open access)

Preliminary Results of Natural Icing of an Axial-Flow Turbojet Engine

Memorandum presenting a flight investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. Tail-pipe temperature increased from 761 to 1065 degrees Fahrenheit and the jet thrust decreased from 1234 to 910 pounds during a period of 45 minutes in icing. No general conclusions can be reached from the data because the icing condition was relatively light.
Date: August 6, 1948
Creator: Acker, Loren W.
System: The UNT Digital Library
Preliminary results of natural icing of an axial-flow turbojet engine (open access)

Preliminary results of natural icing of an axial-flow turbojet engine

Report presenting a flight investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. Results regarding the tail-pipe temperature, engine jet thrust, and characteristics of ice formation are provided. No general conclusions can be reached from the data because the icing condition was relatively light.
Date: August 6, 1948
Creator: Acker, Loren W.
System: The UNT Digital Library
Comparison of flight performance of AN-F-58 and AN-F-32 fuels in J35 turbojet engine (open access)

Comparison of flight performance of AN-F-58 and AN-F-32 fuels in J35 turbojet engine

Report presenting a flight investigation to determine the comparative performance of AN-F-58 and AN-F-32 fuels in a 4000-pound-thrust turbojet engine. The fuels were equivalent over the range of conditions investigated. Results regarding corrected net thrust, corrected jet-fuel consumption, variation of corrected tail-pipe temperature, combustor blow-out speeds, and visual observations of the jet exhaust are provided.
Date: April 7, 1949
Creator: Acker, Loren W. & Kleinknecht, Kenneth S.
System: The UNT Digital Library
Effects of inlet icing on performance of axial-flow turbojet engine in natural icing conditions (open access)

Effects of inlet icing on performance of axial-flow turbojet engine in natural icing conditions

A flight investigation in natural icing conditions was conducted to determine the effect of inlet ice formations on the performance of axial-flow turbojet engines. The results are presented for icing conditions ranging from a liquid-water content of 0.1 to 0.9 gram per cubic meter and water-droplet size from 10 to 27 microns at ambient-air temperature from 13 to 26 degrees F. The data show time histories of jet thrust, air flow, tail-pipe temperature, compressor efficiency, and icing parameters for each icing encounter. The effect of inlet-guide-vane icing was isolated and shown to account for approximately one-half the total reduction in performance caused by inlet icing.
Date: May 25, 1950
Creator: Acker, Loren W. & Kleinknecht, Kenneth S.
System: The UNT Digital Library
Flight Comparison of Performance and Cooling Characteristics of Exhaust-Ejector Installation with Exhaust-Collector-Ring Installation (open access)

Flight Comparison of Performance and Cooling Characteristics of Exhaust-Ejector Installation with Exhaust-Collector-Ring Installation

Flight and ground investigations have been made to compare an exhaust-ejector installation with a standard exhaust-collector-ring installation on air-cooled aircraft engines in a twin-engine airplane. The ground investigation allowed that, whereas the standard engine would have overheated above 600 horsepower, the engine with exhaust ejectors cooled at take-off operating conditions at zero ram. The exhaust ejectors provided as much cooling with cowl flaps closed as the conventional cowl flaps induced when full open at low airspeeds. The propulsive thrust of the exhaust-ejector installation was calculated to be slightly less than the thrust of the collector-ring-installation.
Date: February 14, 1947
Creator: Acker, Loren W. & Kleinknecht, Kenneth S.
System: The UNT Digital Library
Accelerations in fighter-airplane crashes (open access)

Accelerations in fighter-airplane crashes

From Introduction: "This report describes some measurements of these quantities obtained by crashing fighter aircraft under circumstances approximating those observed in service."
Date: November 4, 1957
Creator: Acker, Loren W.; Black, Dugald O. & Moser, Jacob C.
System: The UNT Digital Library
Flying qualities of a high-performance personal-owner airplane (open access)

Flying qualities of a high-performance personal-owner airplane

Report presenting an investigation to measure the flying qualities of a high-performance personal-owner airplane to investigate the possible causes of instrument flying accidents with that type of aircraft. Testing indicated that the lack of aerodynamic stall warning and rapid roll-off at the stall could contribute to stall-spin accidents with high-performance personal-owner aircraft. Results regarding the handling qualities and the control under instrument flying conditions are provided.
Date: November 8, 1951
Creator: Adams, James J. & Whitten, James B.
System: The UNT Digital Library
Tests of a centering spring used as an artificial feel device on the elevator of a fighter airplane (open access)

Tests of a centering spring used as an artificial feel device on the elevator of a fighter airplane

Report presenting tests to investigate the use of a simple centering spring, which had no variation of force gradient with impact pressure, as an artificial feel device for the elevator control of a fighter airplane. Testing was conducted using a Chance Vought F4U-4B airplane equipped with power controls. Results regarding the force experienced and effects of the feel system are provided.
Date: September 12, 1952
Creator: Adams, James J. & Whitten, James B.
System: The UNT Digital Library
Tests of a Horizontal-Tail Model through the Transonic Speed Range by the NACA Wing-Flow Method (open access)

Tests of a Horizontal-Tail Model through the Transonic Speed Range by the NACA Wing-Flow Method

"A 1/12-scale model of a horizontal tail of a fighter airplane was tested through the transonic speeds in the high-speed flow over an airplane wing, the surface of which served as a reflection plane for the model. Measurements of lift, elevator-hinge moment, angle of attack, and elevator angle were made in the Mach number range from 0.75 to 1.04 for elevator deflections ranging from 10 degrees to minus 10 degrees, and for angles of attack of minus 1.2 degrees, 0.4 degrees, and 3.4 degrees. The equipment used to measure the hinge moments of the model proved to be unsatisfactory, and for this reason the hinge-moment data are considered to be only qualitative" (p. 1).
Date: April 11, 1947
Creator: Adams, Richard E. & Silsby, Norman S.
System: The UNT Digital Library
Investigation of Downwash, Sidewash, and Mach Number Distribution Behind a Rectangular Wing at a Mach Number of 2.41 (open access)

Investigation of Downwash, Sidewash, and Mach Number Distribution Behind a Rectangular Wing at a Mach Number of 2.41

"An investigation of the nature of the flow field behind a rectangular circular-arc wing has been conducted in the Langley 9-inch supersonic tunnel. Pitot- and static-pressure surveys covering a region of flow behind the wing have been made together with detailed pitot surveys throughout the region of the wake. In addition, the flow direction has been measured using a weathercocking vane measurements. Theoretical calculations of the variation of both downwash and sidewash with angle of attack using Lagerstrom's superposition method have been made" (p. 1).
Date: September 14, 1950
Creator: Adamson, D. & Boatright, William B.
System: The UNT Digital Library
Effects of Combinations of Aspect Ratio and Sweepback at High Subsonic Mach Numbers (open access)

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

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.
System: The UNT Digital Library
Horizontal-Tail Parameters as Determined From Flight-Test Tail Loads on a Flexible Swept-Wing Jet Bomber (open access)

Horizontal-Tail Parameters as Determined From Flight-Test Tail Loads on a Flexible Swept-Wing Jet Bomber

Report presenting an analysis of horizontal-tail loads on a flexible multi-engined jet-propelled swept-wing medium bomber to determine the tail lift-curve slope due to tail angle of attack, tail-lift curve slope due to elevator deflection, tail pitching-moment coefficient due to elevator deflection, downwash factor, and elevator effectiveness factor. The effect of the stabilizer, effects of elevator flexibility, and effects of wing stability are presented.
Date: January 17, 1957
Creator: Aiken, William S., Jr. & Fisher, Raymond A.
System: The UNT Digital Library
Strain-Gage Measurements of Buffeting Loads on a Jet-Powered Bomber Airplane (open access)

Strain-Gage Measurements of Buffeting Loads on a Jet-Powered Bomber Airplane

Buffet boundaries, buffeting-load increments for the stabilizers and elevators, and buffeting bending-moment increments for the stabilizers and wings as measured in gradual maneuvers for a jet-powered bomber airplane are presented. The buffeting-load increments were determined from strain-gage measurements at the roots or hinge supports of the various surfaces considered. The Mach numbers of the tests ranged from 0.19 to 0.78 at altitudes close to 30,000 feet. The predominant buffet frequencies were close to the natural frequencies of the structural components. The buffeting-load data, when extrapolated to low-altitude conditions, indicated loads on the elevators and stabilizers near the design limit loads. When the airplane was held in buffeting, the load increments were larger than when recovery was made immediately.
Date: March 19, 1951
Creator: Aiken, William S., Jr. & See, John A.
System: The UNT Digital Library
Drag Measurements of a 34 Degree Swept-Forward and Swept-Back NACA 65-009 Airfoil of Aspect Ratio 2.7 as Determined by Flight Tests at Supersonic Speeds (open access)

Drag Measurements of a 34 Degree Swept-Forward and Swept-Back NACA 65-009 Airfoil of Aspect Ratio 2.7 as Determined by Flight Tests at Supersonic Speeds

Report presenting the results of flight testing to determine the zero-lift drag of an NACA 65-009 airfoil at a specified aspect ratio. The results are compared to previous testing of unswept and swept-back arrangements. The swept-forward and swept-back airfoils were found to produce lower values of zero-drag lift than the unswept airfoil.
Date: February 20, 1947
Creator: Alexander, Sidney R.
System: The UNT Digital Library
Drag Measurements of a Swept-Back Wing Having Inverse Taper as Determined by Flight Tests at Supersonic Speeds (open access)

Drag Measurements of a Swept-Back Wing Having Inverse Taper as Determined by Flight Tests at Supersonic Speeds

Report discussing the results of flight tests to determine the drag at zero lift of a swept-back wing of inverse taper using an NACA 65-009 airfoil. The data was compared to untapered wings with a similar degree of sweepback. The tapered wing was found to have a lower drag coefficient than the 34-degree swept-back untapered wing but a higher drag coefficient than the 45-degree swept-back untapered wing.
Date: April 8, 1947
Creator: Alexander, Sidney R.
System: The UNT Digital Library
Drag Measurements of Symmetrical Circular-Arc and NACA 65-009 Rectangular Airfoils Having an Aspect Ratio of 2.7 as Determined by Flight Tests at Supersonic Speeds (open access)

Drag Measurements of Symmetrical Circular-Arc and NACA 65-009 Rectangular Airfoils Having an Aspect Ratio of 2.7 as Determined by Flight Tests at Supersonic Speeds

Report discussing testing to determine the drag characteristics at zero lift of a wing with a circular-arc airfoil section with a maximum thickness of 9 percent chord. The results were compared to previous testing on an NACA 65-009 airfoil. It was found that the NACA airfoil had lower drag coefficients than the circular-arc airfoil tested in this experiment.
Date: March 7, 1947
Creator: Alexander, Sidney R.
System: The UNT Digital Library