The effect of the propeller slipstream on the characteristics of submerged inlets (open access)

The effect of the propeller slipstream on the characteristics of submerged inlets

Report presenting a wind-tunnel investigation to determine the effect of propeller operation on the characteristics of submerged inlets. The tests were performed with a model of a hypothetical fighter airplane powered by a turbine-propeller unit. The propeller had eight blades with thin airfoil shanks and dual rotation and the submerged inlets were placed in the fuselage behind the propeller and forward of the wing.
Date: September 9, 1949
Creator: Delany, Noel K.
System: The UNT Digital Library
Investigations on the Stability, Oscillation, and Stress Conditions of Airplanes With Tab Control: Second Partial Report: Application of the Solutions Obtained in the First Partial Report to Tab-Controlled Airplanes (open access)

Investigations on the Stability, Oscillation, and Stress Conditions of Airplanes With Tab Control: Second Partial Report: Application of the Solutions Obtained in the First Partial Report to Tab-Controlled Airplanes

The first partial report, FB 2000, contained a discussion of the derivation of the equations of motion and their solutions for a tab-controlled airplane; the results obtained there are now to be applied to the longitudinal motion of tab-controlled airplanes. In view of the abundance of structural factors and aerodynamic parameters, a general discussion of the problems is unfeasible. Thus it is demonstrated on the basis of examples what stability, oscillation, and stress conditions are to be expected for tab-controlled airplanes. (author).
Date: September 1949
Creator: Filzek, B.
System: The UNT Digital Library
Attainable Circulation About Airfoils in Cascade (open access)

Attainable Circulation About Airfoils in Cascade

"From consideration of available information on boundary-layer behavior, a relation among profile thickness, maximum surface velocity, Reynolds number, velocity diagram, and solidity is established for a cascade of airfoils immersed in a two-dimensional incompressible fluid flow. Several cascades are computed to show the effect of various cascade design parameters on minimum required cascade solidity. Comparisons with experimentally determined blade performance show that the derived blade loadings are equal or higher for moderate flow deceleration and somewhat lower for large deceleration. Blades with completely laminar flow appear practical for impulse or reaction blading" (p. 117).
Date: September 1949
Creator: Goldstein, Arthur W. & Mager, Artur
System: The UNT Digital Library
Theoretical analysis of various thrust-augmentation cycles for turbojet engines (open access)

Theoretical analysis of various thrust-augmentation cycles for turbojet engines

"The results of analytical studies of tail-pipe-burning, water-injection, and bleedoff methods of thrust augmentation are presented that provide an insight into the operating characteristics of these augmentation methods and summarizes the performance that may be obtained when applied to a typical turbojet engine. A brief description of the principles of operation of each augmentation method is given, together with curves that illustrate the effects of the principal design and operating variables of the augmentation system on the thrust and the liquid consumption of the engine. The necessity of designing tail-pipe burners with a low burner-inlet velocity, a low burner drag, and a high diffuser efficiency in order to obtain a high thrust augmentation and to minimize the loss in engine performance during nonburning operation is illustrated" (p. 593).
Date: September 2, 1949
Creator: Lundin, Bruce T.
System: The UNT Digital Library
An introduction to the physical aspects of helicopter stability (open access)

An introduction to the physical aspects of helicopter stability

In order to provide engineers interested in rotating-wing aircraft, but with no specialized training in stability theory, some understanding of the factors that influence the flying qualities of the helicopter, an explanation is made of both the static stability and the stick-fixed oscillation in hovering and forward flight in terms of fundamental physical quantities. Three significant stability factors -- static stability with angle of attack, static stability with speed, and damping due to a pitching or rolling velocity -- are explained in detail.
Date: September 19, 1949
Creator: Gessow, Alfred & Amer, Kenneth B.
System: The UNT Digital Library
Aerodynamic Characteristics of a 0.5-Scale Model of the Fairchild XSAM-N-2 Lark Missile at High Subsonic Speeds (open access)

Aerodynamic Characteristics of a 0.5-Scale Model of the Fairchild XSAM-N-2 Lark Missile at High Subsonic Speeds

"An investigation was conducted to determine the longitudinal- and lateral-stability characteristics of a 0.5-scale model of the Fairchild Lark missile. The model was tested with 0 deg and with 22.5 deg of roll. Three horizontal wings having NACA 16-009, 16-209, and 64A-209 sections were tested. Pressures were measured on both pointed and blunt noses" (p. 1).
Date: September 28, 1949
Creator: Martin, Andrew & Hunter, Harlo A.
System: The UNT Digital Library
Preliminary Analysis of Axial-Flow Compressors Having Supersonic Velocity at the Entrance of the Stator (open access)

Preliminary Analysis of Axial-Flow Compressors Having Supersonic Velocity at the Entrance of the Stator

"A supersonic compressor design having supersonic velocity at the entrance of the stator is analyzed on the assumption of two-dimensional flow. The rotor and stator losses assumed in the analysis are based on the results of preliminary supersonic cascade tests. The results of the analysis show that compression ratios per stage of 6 to 10 can be obtained with adiabatic efficiency between 70 and 80 percent. Consideration is also given in the analysis to the starting, stability, and range of efficient performance of this type of compressor" (p. 1).
Date: September 12, 1949
Creator: Ferri, Antonio
System: The UNT Digital Library
Behavior of the Laminar Boundary Layer for Periodically Oscillating Pressure Variation (open access)

Behavior of the Laminar Boundary Layer for Periodically Oscillating Pressure Variation

"The calculation of the phenomena within the boundary layer of bodies immersed in a flow underwent a decisive development on the basis of L. Prandtl's trains of thought, stated more than forth years ago, and by numerous later treatises again and again touching upon them. The requirements of the steadily improving aerodynamics of airplanes have greatly increased with the passing of time and recently research became particularly interested in such phenomena in the boundary layer as are caused by small external disturbances. Experimental results suggest that, for instance, slight fluctuations in the free stream velocities as they occur in wind tunnels or slight wavelike deviations of outer wing contours from the prescribed smooth course as they originate due to construction inaccuracies may exert strong effects on the extent of the laminar boundary layer on the body and thus on the drag" (p. 1).
Date: September 1949
Creator: Quick, August Wilhelm & Schröder, K.
System: The UNT Digital Library
Theory of Characteristics (open access)

Theory of Characteristics

The theory of characteristics will be presented generally for quasilinear differential equations of the second order in two variables. This is necessary because of the manifold requirements to be demanded from the theory of characteristics.
Date: September 1949
Creator: Tollmien, W.
System: The UNT Digital Library
Smooth-Water Landing Stability and Rough-Water Landing and Take-Off Behavior of a 1/13-Scale Model of the Consolidated Vultee Skate 7 Seaplane, TED No. NACA DE 338 (open access)

Smooth-Water Landing Stability and Rough-Water Landing and Take-Off Behavior of a 1/13-Scale Model of the Consolidated Vultee Skate 7 Seaplane, TED No. NACA DE 338

A model of the Consolidated Vultee Aircraft Corporation Skate 7 seaplane was tested in Langley tank no. 2. Presented without discussion in this paper are landing stability in smooth water, maximum normal accelerations occurring during rough-water landings, and take-off behavior in waves.
Date: September 8, 1949
Creator: McKann, Robert F.; Coffee, Claude W. & Arabian, Donald D.
System: The UNT Digital Library
The Static-Pressure Error of a Wing Airspeed Installation of the McDonnell XF-88 Airplane in Dives to Transonic Speeds (open access)

The Static-Pressure Error of a Wing Airspeed Installation of the McDonnell XF-88 Airplane in Dives to Transonic Speeds

"Measurements were made, in dives to transonic speeds, of the static-pressure position error at a distance of one chord ahead of the McDonnell XF-88 airplane. The airplane incorporates a wing which is swept back 35 deg along the 0.22 chord line and utilizes a 65-series airfoil with a 9-percent-thick section perpendicular to the 0.25-chord line. The section in the stream direction is approximately 8-percent thick. Data up to a Mach number of about 0.97 were obtained within an airplane normal-force-coefficient range from about 0.05 to about 0.68" (p. 1).
Date: September 23, 1949
Creator: Goodman, Harold R.
System: The UNT Digital Library
Report on Investigation of Developed Turbulence (open access)

Report on Investigation of Developed Turbulence

"The recent experiments by Jakob and Erk, on the resistance of flowing water in smooth pipes, which are in good agreement with earlier measurements by Stenton and Pannell, have caused me to change my opinion that the empirical Blasius law (resistance proportional to the 7/4 power of the mean velocity) was applicable up to arbitrarily high Reynolds numbers. According to the new tests the exponent approaches 2 with increasing Reynolds number, where it remains an open question whether or not a specific finite limiting value of the resistance factor lambda is obtained at R = infinity. With the collapse of Blasius' law the requirements which produced the relation that the velocity in the proximity of the wall varied in proportion to the 7th root of the wall distance must also become void" (p. 1).
Date: September 19, 1949
Creator: Prandtl, L.
System: The UNT Digital Library
Investigations on the Stability, Oscillation, and Stress Conditions of Airplanes with Tab Control: First Partial Report. Derivation of the Equations of Motion and their General Solutions (open access)

Investigations on the Stability, Oscillation, and Stress Conditions of Airplanes with Tab Control: First Partial Report. Derivation of the Equations of Motion and their General Solutions

"For the design and the construction of airplanes the control is of special significance, not only with regard to the flight mechanical properties but also for the proportional arrangement of wing unit, fuselage, and tail unit. Whereas these problems may be regarded as solved for direct control of airplane motions, that is, for immediate operation of the control surfaces, they are not clarified as to oscillations, stability, and stress phenomena occurring in flight motions with Indirect control, as realized for instance in tab control" (p. 1).
Date: September 1949
Creator: Filzek, B.
System: The UNT Digital Library
Performance of Single-Stage Turbine of Mark 25 Torpedo Power Plant with Two Nozzles and Three Rotor-Blade Designs (open access)

Performance of Single-Stage Turbine of Mark 25 Torpedo Power Plant with Two Nozzles and Three Rotor-Blade Designs

From Summary: "A single-stage modification of the turbine from a Mark 25 torpedo power plant was investigated to determine the performance with two nozzles and three rotor-blade designs. The performance was evaluated in terms of brake, rotor, and blade efficiencies at pressure ratios of 8, 15 (design), and 20. The blade efficiencies with the two nozzles are compared with those obtained with four other nozzles previously investigated with the same three rotor-blade designs."
Date: September 9, 1949
Creator: Schum, Harold J. & Whitney, Warren J.
System: The UNT Digital Library
Hovering and Low-Speed Performance and Control Characteristics of the Kaman Helicopter Rotor System as Determined on the Langley Helicopter Tower. TED No. NACA DE 205 (open access)

Hovering and Low-Speed Performance and Control Characteristics of the Kaman Helicopter Rotor System as Determined on the Langley Helicopter Tower. TED No. NACA DE 205

From Summary: "An investigation has been conducted with the Langley helicopter tower to obtain basic performance and control characteristics of the Raman rotor system. Blade-pitch control is obtained in this configuration by utilizing an auxiliary flap to twist the blades. Rotor thrust and power required were measured for the hovering condition and over a range of wind velocities from 0 to 30 miles per hour. The control characteristics and the transient response of the rotor to various control movements were also measured."
Date: September 27, 1949
Creator: Carpenter, Paul J. & Paulnock, Russell S.
System: The UNT Digital Library
An Analysis of Supersonic Aerodynamic Heating With Continuous Fluid Injection (open access)

An Analysis of Supersonic Aerodynamic Heating With Continuous Fluid Injection

From Introduction: "The aerodynamic heating problem assumes considerable importance at high-supersonic speeds. Sanger and Bredt (reference 1) have calculated the high-speed aerodynamic forces and equilibrium surface temperature at extremely high altitudes where the molecular mean free path is large (free-molecule-flow region) compared with a characteristic body dimension. The theoretical investigation of Lees (reference 2) on the stability of the laminar boundary layer in compressible flow indicates that the laminar boundary layer is completely stable at all Reynolds numbers at supersonic speeds for a sufficiently low ratio of surface temperature to stream temperature."
Date: September 29, 1949
Creator: Klunker, E. B. & Ivey, H. Reese
System: The UNT Digital Library
Hydrodynamic characteristics of a swept planing-tail hull (open access)

Hydrodynamic characteristics of a swept planing-tail hull

Report presenting the hydrodynamic characteristics of a swept planing-tail hull as determined by water tank testing. The hull shape was based on results from previous testing indicating that symmetrical airfoil sections and slender boom-like afterbodies lower the drag. Results regarding spray characteristics, take-off stability and trims, landing stability, resistance, and directional stability are presented.
Date: September 12, 1949
Creator: McKann, Robert E.; Coffee, Claude W. & Arabian, Donald D.
System: The UNT Digital Library
Preliminary Investigation of 3-Inch Slotted Transonic Wind-Tunnel Test Sections (open access)

Preliminary Investigation of 3-Inch Slotted Transonic Wind-Tunnel Test Sections

Memorandum describing preliminary investigations of two 3-inch-diameter slotted test sections over a range of pressure ratios from 1.3 to 10.0. The two test sections varied based on the number of slots and amount of open space, but they showed no appreciable difference in performance. Results regarding the slots with no chamber around the test section and with a closed chamber around the test section are provided.
Date: September 9, 1949
Creator: Bates, George P.
System: The UNT Digital Library
Preliminary Wind-Tunnel Investigation at High-Subsonic Speeds of Planing-Tail, Blended, and Airfoil-Forebody Swept Hulls (open access)

Preliminary Wind-Tunnel Investigation at High-Subsonic Speeds of Planing-Tail, Blended, and Airfoil-Forebody Swept Hulls

Report presenting an investigation in the high-speed 7- by 10-foot tunnel to determine the high-subsonic aerodynamic characteristics of three different types of flying-boat hull: a planing-tail hull, a blended hull, and an airfoil-forebody swept hull.
Date: September 12, 1949
Creator: Riebe, John M. & MacLeod, Richard G.
System: The UNT Digital Library
Flight Investigation of the Effect of Boundary-Layer Suction on Profile-Drag Coefficient at Supercritical Mach Numbers (open access)

Flight Investigation of the Effect of Boundary-Layer Suction on Profile-Drag Coefficient at Supercritical Mach Numbers

Memorandum presenting flight tests with a fighter airplane to study the effect of boundary-layer suction aft of the shock wave on airfoil drag at supercritical Mach numbers and high Reynolds numbers. Airfoil chord force was determined from pressure-distribution measurements obtained at a range of Mach numbers at steady dives. Results of the tests showed no measurable effect of suction for the suction coefficient available.
Date: September 20, 1949
Creator: Skoog, Richard B.
System: The UNT Digital Library
Wind-tunnel investigation of horizontal tails. 5: 45 degree swept-back plan form of aspect ratio 2 (open access)

Wind-tunnel investigation of horizontal tails. 5: 45 degree swept-back plan form of aspect ratio 2

Report presenting the results of a wind-tunnel investigation of the low-speed aerodynamic characteristics of a 45 degree sweptback horizontal-tail model of aspect ratio 2 and a comparison of these results with results for a model of the same aspect ratio with an unswept hinge line. Results regarding the lift and hinge-moment parameters, static longitudinal stability, effect of Reynolds number, effect of standard roughness, effect of removing elevator nose seal, and visualization of the air flow are provided.
Date: September 27, 1949
Creator: Dods, Jules B., Jr.
System: The UNT Digital Library
Aerodynamic characteristics of a wing with quarter-chord line swept back 60 degrees, aspect ratio 4, taper ratio 0.6, and NACA 65A006 airfoil section: transonic-bump method (open access)

Aerodynamic characteristics of a wing with quarter-chord line swept back 60 degrees, aspect ratio 4, taper ratio 0.6, and NACA 65A006 airfoil section: transonic-bump method

From Introduction: "This paper presents the results of the investigation of the wing-alone and wing-fuelage configurations employing a wing with the quarter-chord line swept back 60^o, aspect ratio 4, taper ratio 0.6, and an NACA 65A006 airfoil section parallel to the free stream."
Date: September 6, 1949
Creator: King, Thomas J., Jr. & Myers, Boyd C., II
System: The UNT Digital Library
Altitude-chamber performance of British Rolls-Royce Nene II engine 1: standard 18.75-inch-diameter jet nozzle (open access)

Altitude-chamber performance of British Rolls-Royce Nene II engine 1: standard 18.75-inch-diameter jet nozzle

Report presenting an altitude-chamber investigation to determine the altitude performance characteristics of the British Rolls-Royce Nene II turbojet engine with a standard 18.75-inch-diameter jet nozzle. Results regarding the simulated flight performance and generalized performance across other altitude and pressure characteristics are provided.
Date: September 23, 1949
Creator: Barson, Zelmar & Wilsted, H. D.
System: The UNT Digital Library
Flow studies in the asymmetric adjustable nozzle of the Ames 6-by 6-foot supersonic wind tunnel (open access)

Flow studies in the asymmetric adjustable nozzle of the Ames 6-by 6-foot supersonic wind tunnel

Report presenting surveys of the flow of the asymmetric adjustable nozzle of the 6- by 6-foot supersonic wind tunnel, which were made to determine the uniformity of the air stream. Test techniques for minimizing the effects of stream irregularities and the results of force and pressure-distribution tests of a swept-wing model are presented to illustrate the effectiveness of these techniques.
Date: September 15, 1949
Creator: Frick, Charles W. & Olson, Robert N.
System: The UNT Digital Library