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Fuel vaporization and its effect on combustion in a high-speed compression-ignition engine
"The tests discussed in this report were conducted to determine whether or not there is appreciable vaporization of the fuel injected into a high-speed compression-ignition engine during the time available for injection and combustion. The effects of injection advance angle and fuel boiling temperature were investigated. The results show that an appreciable amount of the fuel is vaporized during injection even though the temperature and pressure conditions in the engine are not sufficient to cause ignition either during or after injection, and that when the conditions are such as to cause ignition the vaporization process affects the combustion. The results are compared with those of several other investigators in the same field" (p. 629).
Date:
May 4, 1932
Creator:
Rothrock, A. M. & Waldron, C. D.
System:
The UNT Digital Library
The effect of area aspect ratio on the yawing moments of rudders at large angles of pitch on three fuselages
This reports presents the results of measurements made of yawing moments produced by rudder displacement for seven rudders mounted on each of three fuselages at angles of pitch of 0 degree, 8 degrees, 12 degrees, 20 degrees, 30 degrees and 40 degrees. The dimensions of the rudders were selected to cover the range of areas and aspect ratios commonly used, while the ratios of rudder area to fin area and of rudder chord to fin chord were kept approximately constant. An important result of the measurements is to show that increased aspect ratio gives increased yawing moments for a given area, provided the maximum rudder displacement does not exceed 25 degrees. If large rudder displacements are used, the effect of aspect ratio is not so great.
Date:
May 16, 1932
Creator:
Dryden, Hugh L. & Monish, B. H.
System:
The UNT Digital Library
Negative Thrust and Torque Characteristics of an Adjustable-Pitch Metal Propeller
This report presents the results of a series of negative thrust and torque measurements made with a 4 foot diameter model of a conventional aluminum-alloy propeller. The tests were made in the 20-foot propeller-research tunnel of the National Advisory Committee for Aeronautics. The results show that the negative thrust is considerably affected by the shape and size of the body behind the propeller, that the maximum negative thrust increases with decrease in blade-angle setting, and that the drag of a locked propeller may be greatly reduced by feathering it into the wind.
Date:
May 23, 1933
Creator:
Hartman, Edwin P.
System:
The UNT Digital Library
Experimental Verification of the Theory of Wind-Tunnel Boundary Interference
"The results of an experimental investigation on the boundary-correction factor are presented in this report. The values of the boundary-correction factor from the theory, which at the present time is virtually completed, are given in the report for all conventional types of tunnels. With the isolation of certain disturbing effects, the experimental boundary-correction factor was found to be in satisfactory agreement with the theoretically predicted values, thus verifying the soundness and sufficiency of the theoretical analysis" (p. 79).
Date:
May 18, 1933
Creator:
Theodorsen, Theodore & Silverstein, Abe
System:
The UNT Digital Library
Stability of Thin-Walled Tubes Under Torsion
"In this report a theoretical solution is developed for the torsion on a round thin-walled tube for which the walls become unstable. The results of this theory are given by a few simple formulas and curves which cover all cases. The differential equations of equilibrium are derived in a simpler form than previously found, it being shown that many items can be neglected" (p. 3).
Date:
May 5, 1933
Creator:
Donnell, L. H.
System:
The UNT Digital Library
Compilation of Test Data on 111 Free-Spinning Airplane Models Tested in the Langley 15-Foot and 20-Foot Free-Spinning Tunnels
"A compilation of free-spinning-airplane model data on the spin and recovery characteristics of 111 airplanes is presented. These data were previously published in separate memorandum reports and were obtained from free-spinning tests in the Langley 15-foot and the Langley 20-foot free-spinning tunnels. The model test data presented include the steady-spin and recovery characteristics of each model for various combinations of aileron and elevator deflections and for various loadings and dimensional configurations" (p. 1).
Date:
May 15, 1947
Creator:
Malvestuto, Frank S., Jr.; Gale, Lawrence J. & Wood, John H.
System:
The UNT Digital Library
Investigation of Performance of Axial-Flow Compressor of XT-46 Turbine-Propeller Engine 1 - Preliminary Investigation at 50-,70-, and 100-Percent Design Equivalent Speed
From Summary: "An investigation is being conducted to determine the performance of the 12-stage axial-flow compressor of the XT-46 turbine-propeller engine. This compressor was designed to produce a pressure ratio of 9 at an adiabatic efficiency of 0.86. The design pressure ratios per stage were considerably greater than any employed in current aircraft gas-turbine engines using this type of compressor. The compressor performance was evaluated at two stations."
Date:
May 22, 1950
Creator:
Creagh, John W. R. & Sandercock, Donald M.
System:
The UNT Digital Library
A General Integral Form of the Boundary-Layer Equation for Incompressible Flow With an Application to the Calculation of the Separation Point of Turbulent Boundary Layers
"A general integral form of the boundary-layer equation, valid for either laminar or turbulent incompressible boundary-layer flow, is derived. By using the experimental finding that all velocity profiles of the turbulent boundary layer form essentially a single-parameter family, the general equation is changed to an equation for the space rate of change of the velocity-profile shape parameter. The lack of precise knowledge concerning the surface shear and the distribution of the shearing stress across turbulent boundary layers prevented the attainment of a reliable method for calculating the behavior of turbulent boundary layers" (p. 1067).
Date:
May 22, 1950
Creator:
Tetervin, Neal & Lin, Chia Chiao
System:
The UNT Digital Library
An analysis of base pressure at supersonic velocities and comparison with experiment
From Introduction: "The primary purpose of the investigation described in the present described in the present report is to formulate a method which is of value for qualitative calculations of base pressure both on airfoils and bodies."
Date:
May 11, 1951
Creator:
Chapman, Dean R.
System:
The UNT Digital Library
The Effectiveness at High Speeds of a 20-Percent-Chord Plain Trailing-Edge Flap on the NACA 65-210 Airfoil Section
"An analysis has been made of the lift-control effectiveness of a 20-percent-chord plain trailing-edge flap on the NACA 65-210 airfoil section from section lift-coefficient data obtained at Mach numbers from 0.3 to 0.875. In addition, the effectiveness of the plain flap as a lift-control device has been compared with the corresponding effectiveness of both a spoiler and a dive-recovery flag on the INCA 65-210 airfoil section" (p. 1).
Date:
May 6, 1947
Creator:
Stivers, Louis S., Jr.
System:
The UNT Digital Library
Fatigue strength and related characteristics of joints in 24S-T Alclad sheet
Report includes tension fatigue test results on the following types of samples of 0.040-inch alclad 24s-t: (1) monoblock sheet samples as received and after a post-aging heat treatment, (2) "sheet efficiency" samples (two equally stressed sheets joined by a single transverse row of spot welds) both as received and after post-aging, (3) spot-welded lap-joint samples as received and after post-aging, and (4) roll-welded lap-joint samples. (author).
Date:
May 1944
Creator:
Russell, H. W.; Jackson, L. R.; Grover, H. J. & Beaver, W. W.
System:
The UNT Digital Library
Cooling Characteristics of the V-1650-7 Engine, 1, Coolant-Flow Distribution, Cylinder Temperatures, and Heat Rejections at Typical Operating Conditions
From Summary: "An investigation was conducted to determine the coolant-flow distribution, the cylinder temperatures, and the heat rejections of the V-1650-7 engine . The tests were run a t several power levels varying from minimum fuel consumption to war emergency power and at each power level the coolant flows corresponded to the extremes of those likely to be encountered in typical airplane installations, A mixture of 30-percent ethylene glycol and 70-percent water was used as the coolant. The temperature of each cylinder was measured between the exhaust valves, between the intake valves, in the center of the head, on the exhaust-valve guide, at the top of the barrel on the exhaust side, and on each exhaust spark-plug gasket."
Date:
May 23, 1947
Creator:
Povolny, John H. & Bogdan, Louis J.
System:
The UNT Digital Library
The Effect of Internal Pressure on the Buckling Stress of Thin-Walled Circular Cylinders Under Torsion
"The results of a series of tests to determine the effect of internal pressure on the buckling load of a thin cylinder under an applied torque indicated that internal pressure raises the shear buckling stress. The experimental results were analyzed with the aid of previously developed theory and a simple interaction formula was derived" (p. 1).
Date:
May 1944
Creator:
Crate, Harold; Batdorf, S. B. & Baab, George W.
System:
The UNT Digital Library
Torsion Tests of Stiffened Circular Cylinders
"The design of curved sheet panels to resist shear involves a consideration of several factors: the buckling resistance of the sheet, the stress at which buckling becomes permanent, and the strength which may be developed beyond the buckling limit by tension-field action. Although some experimental as well as theoretical work has been done on the buckling and tension-field phases of this problem, neither of these types of action appears to be very well understood. This report presents the results of the first series of torsion tests of stiffened circular cylinders to be completed in connection with this study at Aluminum Research Laboratories" (p. 1).
Date:
May 1944
Creator:
Moore, R. L. & Wescoat, C.
System:
The UNT Digital Library
Drag and Longitudinal Trim at Low Lift of the North American YF-100A Airplane at Mach Numbers from 0.76 to 1.77 as Determined from the Flight Test of a 0.11-Scale Rocket Model
Drag and longitudinal trim at low lift of the North American YF-100A airplane at Mach numbers from 0.76 to 1.77 as determined from the flight test of a 0.11-scale rocket model are presented herein. Also included are some longitudinal stability and some qualitative pitch-damping data.
Date:
May 14, 1953
Creator:
Blanchard, Willard S., Jr.
System:
The UNT Digital Library
Discussion of problems relating to the safety of aviation. Part 1
The object of the present treatise is to examine the present status of aerial safety and to review the efforts of various commissions to promote safety.
Date:
May 1928
Creator:
Sabatier, J.
System:
The UNT Digital Library
Discussion of problems relating to the safety of aviation. Part 2
This report focuses on structural strength and engine design in building and designing safer aircraft.
Date:
May 1928
Creator:
Sabatier, J.
System:
The UNT Digital Library
Flutter and oscillating air-force calculations for an airfoil in two-dimensional supersonic flow
A connected account is given of the Possio theory of non-stationary flow for small disturbances in a two-dimensional supersonic flow and of its application to the determination of the aerodynamic forces on an oscillating airfoil. Further application is made to the problem of wing flutter in the degrees of freedom - torsion, bending, and aileron rotations. Numerical tables for flutter calculations are provided for various values of the Mach number greater than unity. Results for bending-torsion wing flutter are shown in figures and are discussed. The static instabilities of divergence and aileron reversal are examined as is a one-degree-of-freedom case of torsional oscillatory instability.
Date:
May 29, 1946
Creator:
Garrick, I. E. & Rubinow, S. I.
System:
The UNT Digital Library
The Effect of an Operating Propeller on the Aerodynamic Characteristics of a 1/10-Scale Model of the Lockheed XFV-1 Airplane at High Subsonic Speeds (TED No. NACA DE-377)
"An investigation was conducted in the Ames 12-foot pressure wind tunnel to determine the effect of an operating propeller on the aerodynamic characteristics of a 1/19-scale model of the Lockheed XFV-1 airplane. Several full-scale power conditions were simulated at Mach numbers from 0.50 to 0.92; the.Reynolds number was constant at 1.7 million. Lift, longitudinal force, pitch, roll, and yaw characteristics, determined with and without power, are presented for the complete model and for various combinations of model components" (p. 1).
Date:
May 6, 1952
Creator:
Sutton, Fred B. & Buell, Donald A.
System:
The UNT Digital Library
Approximate analysis of effects of large deflections and initial twist on torsional stiffness of a cantilever plate subjected to thermal stresses
From Summary: "An approximate analysis of the nonlinear effects of initial twist and large deflections on the torsional stiffness of a cantilever plate subjected to a nonuniform temperature distribution is presented. The Von Karman large-deflection equations are satisfied through the use of a variational principle. The results show that initial twist and applied moments can have significant effects on the changes in stiffness produced by nonuniform heating, particularly in the region of the buckling temperature difference. Results calculated by this approximate analysis are in satisfactory agreement with measured torsional deformations and changes in natural frequency."
Date:
May 15, 1957
Creator:
Heldenfels, Richard R. & Vosteen, Louis F.
System:
The UNT Digital Library
Aerodynamic theory and tests of strut forms 2
This report presents the second of two studies under the same title. In this part five theoretical struts are developed from distributed sources and sinks and constructed for pressure and resistance tests in a wind tunnel. The surface pressures for symmetrical inviscid flow are computed for each strut from theory and compared with those found by experiment. The theoretical and experimental pressures are found to agree quantitatively near the bow, only qualitatively over the suction range, the experimental suctions being uniformly a little low, and not at all near the stern.
Date:
May 1929
Creator:
Smith, R. H.
System:
The UNT Digital Library
Tests of large airfoils in the propeller research tunnel, including two with corrugated surfaces
This report gives the results of the tests of seven 2 by 12 foot airfoils (Clark Y, smooth and corrugated, Gottingen 398, N.A.C.A. M-6, and N.A.C.A. 84). The tests were made in the propeller research tunnel of the National Advisory Committee for Aeronautics at Reynolds numbers up to 2,000,000. The Clark Y airfoil was tested with three degrees of surface smoothness. Corrugating the surface causes a flattening of the lift curve at the burble point and an increase in drag at small flying angles.
Date:
May 24, 1929
Creator:
Wood, Donald H.
System:
The UNT Digital Library
The Gaseous Explosive Reaction at Constant Pressure: The Reaction Order and Reaction Rate
The data given in this report covers the explosive limits of hydrocarbon fuels. Incidental to the purpose of the investigation here reported, the explosive limits will be found to be expressed for the condition of constant pressure, in the fundamental terms of concentrations (partial pressures) of fuel and oxygen.
Date:
May 9, 1929
Creator:
Stevens, F. W.
System:
The UNT Digital Library
Combustion in a High-Speed Compression-Ignition Engine
"An investigation conducted to determine the factors which control the combustion in a high-speed compression-ignition engine is presented. Indicator cards were taken with the Farnboro indicator and analyzed according to the tangent method devised by Schweitzer. The analysis show that in a quiescent combustion chamber increasing the time lag of auto-ignition increases the maximum rate of combustion. Increasing the maximum rate of combustion increases the tendency for detonation to occur" (p. 63).
Date:
May 21, 1931
Creator:
Rothrock, A. M.
System:
The UNT Digital Library