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Preliminary Free-Flight Investigation of the Effect of Airfoil Section on Aileron Rolling Effectiveness at Transonic and Supersonic Speeds
"Results have been obtained by means of a free-flight technique utilizing rocket propulsion which indicate that aileron-rolling-effectiveness characteristics are affected adversely by variations in airfoil section which procedure large increases in the trailing-edge angle" (p. 1).
Date:
June 25, 1948
Creator:
Sandahl, Carl A.
System:
The UNT Digital Library
The Effects of Fuel Sloshing on the Lateral Stability of a Free-Flying Airplane Model
Memorandum presenting an investigation in the free-flight tunnel to determine the effect of the sloshing of fuel in partly filled, unbaffled tanks on the lateral stability of a free-flying model. Flight tests were made to determine the effects of the water sloshing for different depths of water and various masses and moments of inertia of the model. The sloshing caused small-amplitude, high-frequency lateral oscillations which were superimposed on the normal Dutch roll oscillation so that the lateral motions of the model appeared jerky.
Date:
June 29, 1948
Creator:
Smith, Charles C., Jr.
System:
The UNT Digital Library
Ice protection of turbojet engines by inertia separation of water 2: single-offset-duct system
Investigation of a single-offset-duct system designed to prevent entrance of water into a turbojet engine was conducted on a half-scale nacelle model. An investigation was made to determine ram-pressure recovery and radial velocity profiles at the compressor section and icing characteristics of such a duct system. At a design inlet velocity of 0.77, the maximum ram-pressure recovery attained with effective water-separating inlet was 77 percent, which is considerably less than attainable with a direct-ram inlet. Continuous heating of the accessory-housing surface would be required for inlets that have a small ice storage space.
Date:
June 8, 1948
Creator:
von Glahn, Uwe
System:
The UNT Digital Library
Investigation at supersonic speed (M = 1.53) of the pressure distribution over a 63 degrees swept airfoil of biconvex section at zero lift
Report presenting an investigation of the distribution of pressure at zero lift over the surface of a swept airfoil of biconvex section. The measured pressures are compare with theoretical values calculated from thin-airfoil theory. Results regarding pressure distributions, drag, and boundary-layer studies are provided.
Date:
June 10, 1948
Creator:
Frick, Charles W. & Boyd, John W.
System:
The UNT Digital Library
Preliminary investigation of combustion in flowing gas with various turbulence promoters
Report presenting an investigation of combustion occurring downstream of various turbulence promoters in a 20-inch length of a 1 7/8-inch inside-diameter, water-jacketed tubing using premixed vaporized fuel and air. Among the turbulence promoters investigated were flat plates perforated with 1/8-inch diameter holes, 1/4-inch diameter holes, and a single large hole to give 12.4, 17.2, and 21.5 percent open area respectively.
Date:
June 7, 1948
Creator:
Haddock, Gordon W. & Childs, J. Howard
System:
The UNT Digital Library
Free-Spinning Characteristics of a 1/21-Scale Model of the Douglas AD-2W Airplane: TED No. NACA DE329
Report presenting an investigation to determine the spin and recovery characteristics of a model of the Douglas AD-2W airplane, which has a large radome installation. Results indicated that the plane has satisfactory erect and inverted spin-recovery characteristics. Information about erect spins, inverted spins, and recommended recovery technique is provided.
Date:
June 9, 1948
Creator:
White, Richard P.
System:
The UNT Digital Library
Investigation of wing characteristics at a Mach number of 1.53 2: swept wings of taper ratio 0.5
Measured values of lift, drag, and pitching moment at M(sub o) = 1.53 are presented for seven wings varying in sweep angle from 60 degrees sweepforward to 60 degrees sweepback. All wings had a cambered, double-wedge section 5-percent thick and a common taper ratio of 0.5. The experimental results are compared with the predictions of the linear theory.
Date:
June 28, 1948
Creator:
Vincenti, Walter G.; Van Dyke, Milton D. & Matteson, Frederick H.
System:
The UNT Digital Library
A Design Study of Leading-Edge Inlets for Unswept Wings
Note presenting a practical method, employing a lofting technique, for determining the profile coordinates of an air inlet for the leading edge of an airfoil from formulas which are dependent only on the airfoil coordinates and on the height of the opening. It was found that the base-profile concept of thin-airfoil theory could be applied to a ducted airfoil with satisfactory results. Results regarding design inlets, modified inlets, and end-closure shape are provided.
Date:
June 30, 1950
Creator:
Dannenberg, Robert E.
System:
The UNT Digital Library
A flight investigation and analysis of the lateral-oscillation characteristics of an airplane
Report presenting flight tests to determine the causes of undesirable dynamic lateral-stability characteristics of an airplane. Various rudder modifications were flight tested with the rudder free and fixed over an indicated airspeed range from approximately 200 to 450 miles per hour. Results regarding rudder-fixed characteristics and rudder-free characteristics are provided.
Date:
June 3, 1948
Creator:
Stough, Carl J. & Kauffman, William M.
System:
The UNT Digital Library
Tank investigation of the Grumman JRF-5 airplane fitted with hydro-skis suitable for operation on water, snow, and ice
Report presenting results of a tank investigation of a 1/8-size powered dynamic model of the Grumman JRF-5 airplane fitted with tandem hydro-skis and auxiliary wing-tip skids suitable for operation on water, snow, and ice. Results regarding take-off and landing tests are provided.
Date:
June 12, 1950
Creator:
Wadlin, Kenneth L. & Ramsen, John A.
System:
The UNT Digital Library
Preliminary Analysis of Problem of Determining Experimental Performance of Air-Cooled Turbine 1: Methods for Determining Heat-Transfer Characteristics
In determining the experimental performance of an air-cooled turbine, the heat-transfer characteristics must be evaluated. The suggested formulas that are required to determine these characteristics are presented. The formulas have a form in which dependent parameters are expressed as unknown functions of independent parameters. Methods of experimenting to determine these functions are suggested. In some cases general heat-transfer discussions that lead to the suggested forms of the formulas are given.
Date:
June 12, 1950
Creator:
Ellerbrock, Herman H., Jr. & Ziemer, Robert R.
System:
The UNT Digital Library
Preliminary Analysis of Problem of Determining Experimental Performance of Air-Cooled Turbine 2: Methods for Determining Cooling-Air-Flow Characteristics
In the determination of the performance of an air-cooled turbine, the cooling-air-flow characteristics between the root and the tip of the blades must be evaluated. The methods, which must be verified and the unknown functions evaluated, that are expected to permit the determination of pressure, temperature, and velocity through the blade cooling-air passages from specific investigation are presented.
Date:
June 7, 1950
Creator:
Ellerbrock, Herman H., Jr.
System:
The UNT Digital Library
Combustion-efficiency and altitude-limit investigations of five fuels in an annular turbojet combustor
Report presenting five fuels of boiling temperatures and several hydrocarbon types in a jet-propulsion annular combustor to determine the effect of fuel boiling temperature and paraffinic and aromatic hydrocarbon types on combustion efficiency and altitude operational limit. At the severe inlet-air condition, the highest combustion efficiencies were obtained with the paraffinic and aromatic fuels with low boiling temperatures were found to vary from 30 to 58 percent.
Date:
June 7, 1954
Creator:
Wear, Jerrold D. & Jonash, Edmund R.
System:
The UNT Digital Library
An Investigation of the Low-Speed Characteristics of Two Sharp-Edge Supersonic Inlets Designed for Essentially External Supersonic Compression
Report presenting an investigation of two sharp-edge annular inlets with conical central bodies at low airspeeds in the propeller research tunnel to obtain information concerning the surface-pressure, drag, and pressure-recovery characteristics of the inlets at subsonic flight. Results regarding the nose and inner surface of the diffuser, inlet lips, minimum surface pressures and critical Mach numbers, pressure surveys in inlets, and pressure surveys in diffusers are provided.
Date:
June 6, 1947
Creator:
Dennard, John S.
System:
The UNT Digital Library
Pressure-distribution measurements on a full-scale horizontal tail surface for a Mach number range of 0.20 to 0.70
Report presenting testing of a full-scale, semispan, horizontal tail surface for a jet-propelled fighter airplane in the 16-foot high-speed tunnel to determine the variation of the chordwise and spanwise pressure distributions with Mach number. Surface irregularities were found to cause appreciable distortion of the pressure distribution. Results regarding chordwise distributions, spanwise distribution, effect of Mach number on root bending moment, and estimated critical Mach numbers are provided.
Date:
June 25, 1947
Creator:
Schueller, Carl F.
System:
The UNT Digital Library
Equations for the Design of Two-Dimensional Supersonic Nozzles
Memorandum presenting equations for obtaining the wall coordinates of two-dimensional supersonic nozzles. The equations are based on the application of the method of characteristics to irrotational flow of perfect gases in channels. A brief discussion of characteristics as applied to nozzle design is given to assist in understanding and applying the nozzle-design method of the report.
Date:
June 21, 1948
Creator:
Pinkel, I. Irving
System:
The UNT Digital Library
Effect of Aerodynamic Hysteresis on Critical Flutter Speed at Stall
Memorandum presenting a theoretical analysis of the effect of aerodynamic hysteresis on stalling flutter. The results were applied to a given airfoil and correlation of the experimental and theoretical results was found possible by assuming that the angle of aerodynamic lag varies as the slope of the static-lift curve. It was shown that the phenomenon of stalling flutter can at least in some cases be explained on the basis of an aerodynamic lag or hysteresis effect.
Date:
June 18, 1948
Creator:
Mendelson, Alexander
System:
The UNT Digital Library
Effect of Centrifugal Force on Critical Flutter Speed on a Uniform Cantilever Beam
Report presenting theoretical calculations made by means of semirigid-flutter theory to determine the effect of centrifugal force on the critical flutter speed of a uniform cantilever beam. Calculations are made on airfoils with fundamental bending frequencies up to 2000 radian per second. Centrifugal force can under certain conditions reduce the critical flutter speed.
Date:
June 18, 1948
Creator:
Mendelson, Alexander
System:
The UNT Digital Library
The use of perforated inlets for efficient supersonic diffusion
Report presenting the use of wall perforations on supersonic diffusers to avoid the internal contraction-ratio limitation. Experimental results on a preliminary model of a perforated diffuser at Mach number 1.85 are provided. A theoretical discussion of the flow coefficients and the size and spacing of the perforations are included.
Date:
June 25, 1947
Creator:
Evvard, John C. & Blakey, John W.
System:
The UNT Digital Library
Wind-Tunnel Investigation of Bomb-Bay Configurations Intended to Minimize the Tumbling of Light-Weight Bombs
Report presenting an investigation in the 300 mph 7- by 10-foot tunnel to determine what modifications could be made to conventional bomb bays to reduce the tumbling difficulties experienced with light-weight bombs. The investigation indicated that there is a definite region of reversed flow inside the bomb bay which must be weakened or destroyed if good drops are to be obtained.
Date:
June 25, 1947
Creator:
Kuhn, Richard E. & Polhamus, Edward C.
System:
The UNT Digital Library
High-Speed Wind-Tunnel Tests of a 1/16-Scale Model of the D-558 Research Airplane: D-588-1 Speed-Reduction Brake and Symmetrical-Profile Wing Characteristics
Report presenting the results of pitching-moment, lift, and drag measurements on a model of the D-558-1 with speed reduction brakes and a symmetrical profile wing at a range of Mach numbers. Only a small decrement in Mach number is produced with no nose-inlet flow and the speed-reduction brakes deflected.
Date:
June 15, 1948
Creator:
Wright, John B.
System:
The UNT Digital Library
Experimental investigation at supersonic speeds of twin-scoop duct inlets of equal area 2: effects of slots upon an inlet enclosing 61.5 percent of the maximum circumference of the forebody
Report presenting tests at Mach numbers between 1.36 and 2.01 of a twin-scoop duct inlet that had slots in the walls of the duct contiguous to the forebody and immediately behind the inlet. The mass flow and total-pressure recovery through the diffusor were measured during tests in which the slot length was constant and the slot width and ramp angle were varied. Results regarding mass flow and total-pressure recovery are provided.
Date:
June 9, 1948
Creator:
Davis, Wallace F. & Goldstein, David L.
System:
The UNT Digital Library
Longitudinal Stability and Control Characteristics at Transonic Speeds of a Semispan Airplane Model Having a 45 Degree Sweptback Wing and Tail as Obtained by the Transonic-Bump Method
Report presenting a wind-tunnel investigation using the transonic-bump method to determine the longitudinal stability and control characteristics of a semispan airplane model with a 45 degree sweptback wing and tail at transonic speeds. An increase in the rate of change of the pitching-moment coefficient with lift coefficient at a constant Mach number through the transonic range was noted.
Date:
June 30, 1948
Creator:
Spearman, M. Leroy
System:
The UNT Digital Library
Ice protection of turbojet engines by inertia separation of water 3: annular submerged inlets
Aerodynamic and icing studies were conducted on a one-half-scale model of an annular submerged inlet for use with axial-flow turbojet engines. Pressure recoveries, screen radial-velocity profiles, circumferential mass-flow variations, and icing characteristics were determined at the compressor inlet. In order to be effective in maintaining water-free induction air, the inlet gap must be extremely small and ram-pressure recoveries consequently are low, the highest achieved being 65 percent at inlet-velocity ratio of 0.86. All inlets exhibited considerable screen icing. Severe mass-flow shifts occurred at angles of attack.
Date:
June 8, 1948
Creator:
von Glahn, Uwe
System:
The UNT Digital Library