Effect of Inlet-Guide-Vane Angle on Blade Vibration and Rotating Stall of 13-Stage Axial-Flow Compressor in Turbojet Engine (open access)

Effect of Inlet-Guide-Vane Angle on Blade Vibration and Rotating Stall of 13-Stage Axial-Flow Compressor in Turbojet Engine

Report presenting a blade-vibration and rotating-stall survey on a modified version of a production turbojet engine with a 13-stage axial-flow compressor with a design pressure ratio of 7 and an air flow of 120 pounds per second. This testing was carried out due to the problems rotating stall can cause with both experimental and production axial-flow compressors. Results regarding the rotating-stall patterns, rotor-blade vibrations, radial and axial strength of rotating stall, and maximum rotating-stall speed are provided.
Date: May 22, 1956
Creator: Calvert, Howard F.; Medeiros, Arthur A. & Johnson, Donald F.
System: The UNT Digital Library
The change with mass-flow ratio of the cowl pressure drag of normal-shock inlets at supersonic speeds (open access)

The change with mass-flow ratio of the cowl pressure drag of normal-shock inlets at supersonic speeds

Report presenting pressure-drag coefficients and the changes in these coefficients with mass-flow ratio, which have been measured in tests of six open-nose conical cowls at an angle of attack of 0 degrees. Testing occurred in the Ames 8 by 8-inch supersonic wind tunnel at a range of Mach numbers. Results regarding pressure distributions, change in cowl pressure drag with mass-flow ratio, cowl pressure drag at a given mass-flow ratio, and changes in cowl pressure drag with mass-flow ratio as a function of Mach number are provided.
Date: June 22, 1956
Creator: Davis, Wallace F. & Gowen, Forrest E.
System: The UNT Digital Library
Gas-turbine-engine performance when heat from liquid-cooled turbines is rejected ahead of, within, or behind main compressor (open access)

Gas-turbine-engine performance when heat from liquid-cooled turbines is rejected ahead of, within, or behind main compressor

Report discussing methods, advantages, and disadvantages of locating rotating heat exchangers ahead of, within, and behind the main engine compressor. Heat rejection should occur at the compressor discharge for best engine performance. Results regarding turbojet-engine performance, turboprop-engine performance, and a comparison of engine performance with liquid- and air-cooling are provided.
Date: May 22, 1956
Creator: Esgar, Jack B. & Slone, Henry O.
System: The UNT Digital Library
Fabrication Techniques and Heat-Transfer Results for Cast-Cored Air-Cooled Turbine Blades (open access)

Fabrication Techniques and Heat-Transfer Results for Cast-Cored Air-Cooled Turbine Blades

Memorandum presenting an investigation to devise an air-cooled turbine blade which eliminated the difficulties encountered with brazing in air-cooled-blade fabrication. Techniques were developed for casting air-cooled blades with a large number of relatively small cooling passages near the airfoil surface; two such blades of HS-21 material were operated in a turbojet engine modified for air cooling. Results regarding the heat-transfer characteristics, stress and durability results, and evaluation of cast-cored-blade potential are provided.
Date: June 22, 1956
Creator: Freche, John C. & Oldrieve, Robert E.
System: The UNT Digital Library
Investigation of the Use of Area Suction to Increase the Effectiveness of Trailing-Edge Flaps of Various Spans on a Wing of 45 Degree Sweepback and Aspect Ratio 6 (open access)

Investigation of the Use of Area Suction to Increase the Effectiveness of Trailing-Edge Flaps of Various Spans on a Wing of 45 Degree Sweepback and Aspect Ratio 6

Report discusses the results of an investigation of a model of a wing of 45 degree sweepback and aspect ratio 6 to determine the aerodynamic characteristics and suction requirements for boundary-layer control by means of area suction applied to trailing-edge flaps. Various flap spans and flap deflections were tested. The measured values of the coefficients were compared to the calculated values.
Date: June 22, 1956
Creator: Griffin, Roy N., Jr. & Hickey, David H.
System: The UNT Digital Library
Free-flight measurements of the zero-lift drag of several wings at Mach numbers from 1.4 to 3.8 (open access)

Free-flight measurements of the zero-lift drag of several wings at Mach numbers from 1.4 to 3.8

Report presenting the zero-lift drag of several wings obtained at supersonic Mach numbers in free flight with rocket-propelled models. The wings tested all had the same exposed area, mounted on the same basic body configuration, and had one of four different types of wings.
Date: June 22, 1956
Creator: Jackson, H. Herbert
System: The UNT Digital Library
Effect of Inlet-Guide-Vane Angle on Performance Characteristics of a 13-Stage Axial-Flow Compressor in a Turbojet Engine (open access)

Effect of Inlet-Guide-Vane Angle on Performance Characteristics of a 13-Stage Axial-Flow Compressor in a Turbojet Engine

Report presenting the effect of adjusting compressor inlet-guide-vane angle on overall compressor performance, stage performance, engine thrust, and specific fuel consumption in a 7000-pound-thrust turbojet engine. Data was obtained at several angles and demonstrated that increasing the guide-vane angle decreased the weight flow at the higher compressor speeds. It had no effect on stage performance other than at the first stage, where it reduced maximum flow, pressure, and temperature coefficients.
Date: May 22, 1956
Creator: Medeiros, Arthur A. & Calvert, Howard F.
System: The UNT Digital Library
Investigation of two-stage air-cooled turbine suitable for flight at Mach number of 2.5 1: Velocity-diagram study (open access)

Investigation of two-stage air-cooled turbine suitable for flight at Mach number of 2.5 1: Velocity-diagram study

Report presenting a two-stage air-cooled turbine configuration and its velocity diagrams for use in the design of blade shapes for a set of engine conditions suitable for flight at Mach number 2.5. The method used to determine the velocity diagrams was one in which the turbine frontal areas and rotor hub inlet and outlet velocities were minimized by varying the hub-tip ratio, turbine- to compressor-tip-diameter ratio, and the work split between the first and second stages.
Date: October 22, 1956
Creator: Miser, James W. & Stewart, Warner L.
System: The UNT Digital Library
Temperatures in a J47-25 turbojet-engine turbine section during steady-state and transient operation in an altitude test stand (open access)

Temperatures in a J47-25 turbojet-engine turbine section during steady-state and transient operation in an altitude test stand

Report presenting a J47-25 engine instrumented with thermocouples and operated under steady-state and transient-conditions in an altitude test stand to determine the operating temperatures at altitude in the turbine section of a turbojet engine. Results regarding the temperature effects and transient operation are provided.
Date: May 22, 1956
Creator: Morse, C. R. & Johnston, J. R.
System: The UNT Digital Library
Effect of fuels on screaming in 200-pound-thrust liquid-oxygen - fuel rocket engine (open access)

Effect of fuels on screaming in 200-pound-thrust liquid-oxygen - fuel rocket engine

Report presenting the tendencies of 14 different fuels and three fuel blends to produce high-frequency oscillatory combustion (screaming) in a 200-pound-thrust, water-cooled, liquid-oxygen-fuel rocket engine. The fuels, in order of increasing screaming tendency, were hydrazines, branched-chain paraffins, aromatics, and amines, and straight-chain paraffins. Results regarding screaming tendency and screaming amplitude are provided.
Date: June 22, 1956
Creator: Pass, Isaac & Tischler, Adelbert O.
System: The UNT Digital Library
Performance of a Double-Ramp Side Inlet With Combinations of Fuselage, Ramp, and Throat Boundary-Layer Removal, Mach Number Range, 1.5 to 2.0 (open access)

Performance of a Double-Ramp Side Inlet With Combinations of Fuselage, Ramp, and Throat Boundary-Layer Removal, Mach Number Range, 1.5 to 2.0

Double-ramp side inlet with combinations of fuselage, ramp, and throat boundary layer removal.
Date: October 22, 1956
Creator: Simon, Paul C.
System: The UNT Digital Library
A Simplified Method for Approximating the Transient Motion in Angles of Attack and Sideslip During a Constant Rolling Maneuver (open access)

A Simplified Method for Approximating the Transient Motion in Angles of Attack and Sideslip During a Constant Rolling Maneuver

"The transient motion in angles of attack and sideslip during a constant rolling maneuver has been analyzed. Simplified expressions are presented for the determination of the pertinent modes of motion as well as the modal coefficient corresponding to each mode. Calculations made with and without the derivatives for side force due to sideslip and lift-curve slope indicate that although these derivatives increase the total damping of the system they do not markedly affect the transient motion" (p. 131).
Date: May 22, 1956
Creator: Sternfield, Leonard
System: The UNT Digital Library
Investigation of Two-Stage Counterrotating Compressor. 3: Design of Second-Stage Rotor and Preliminary Over-All Performance (open access)

Investigation of Two-Stage Counterrotating Compressor. 3: Design of Second-Stage Rotor and Preliminary Over-All Performance

At the design speed of a two-stage counterrotating compressor, an overall average pressure ratio of 4.3 was obtained at a specific weight flow of 27.2 pounds per second per square foot frontal area with an adiabatic efficiency of 0.75. Preliminary tests indicate that a weight-flow mismatching exists between the two rotors that causes the first rotor to operate at less than peak efficiency at design speed. At lower speeds, the first stage was forced to operate in the stalled region in single-stage tests. With the second rotor installed, no periodic rotating stall was observed, although random fluctations of similiar magnitude were noted.
Date: October 22, 1956
Creator: Wilcox, Ward W. & Wright, Linwood C.
System: The UNT Digital Library
Investigation of two-stage counterrotating compressor I : design and over-all performance of transonic first compressor stage (open access)

Investigation of two-stage counterrotating compressor I : design and over-all performance of transonic first compressor stage

Report presenting a highly loaded transonic rotor which was designed, built, and tested as part of a two-stage counterrotating-compressor research program. The design conditions were chosen to explore the upper limits of loading and Mach number for the transonic unit. The complete rotor design procedure is presented as well as the recorded stall traces and techniques for obtaining the data.
Date: May 22, 1956
Creator: Wilcox, Ward W. & Wright, Linwood C.
System: The UNT Digital Library